These days, we could do with all the mental strength we can muster. 

Mental strength is the ability to productively regulate your emotions, thoughts, and behaviors, even in the face of adversity. And adversity is in no short supply. If you want to overcome more challenges, achieve more success, experience more happiness and less stress — it takes mental strength. 

After spending decades studying mental strength and interviewing and surveying thousands of people for my recent book, “The Mentally Strong Leader,″ I have good news. The mentally strongest people tend to share certain habits we can learn from. There are patterns I’ve noticed when it comes to what they say (and don’t say) and what they do.

If you always do these eight things, you’re already mentally stronger than most. If you don’t — yet! — you can look to this list as a mini-playbook that will help you level up your mental strength.  

That adage about how you should “leave your emotions at the door” just doesn’t work. If you’ve tried it, you know it’s not that simple.

That said, while mentally strong people are aware of emotions triggered inside, they don’t let those emotions instantly flow through into words or actions. 

They catch their emotions, consider if they’re helpful to express, then decide how to respond. In other words, regarding unhelpful emotions, they catch it, check it, and change it (using the the 3 Cs of cognitive behavioral therapy).

We all contend with doubt. Even the most confident people I’ve interviewed experience doubt. 

Confidence, then, is your ability to manage your relationship with the doubt you’ll inevitably experience. 

The mentally strong have found the right middle ground between overconfident and paralyzed by fear of failure. They acknowledge doubt, but let it sit quietly in the background so they can focus on how they will accomplish something, not if they can accomplish it in the first place.  

Imagine a friend, clearly upset and in need of empathy, was telling you about a relationship they just ended. After listening, would you say: 

“How could you let this relationship fail? It’s all your fault, you jerk!” 

I doubt it. Instead, you might say:

“I appreciate what you’re going through and how much it must hurt. Try not to be so hard on yourself.”

You should take this more compassionate tone with yourself, too. 

When we face setbacks, we often try to go it alone, forgetting that one of the most important things mentally strong people do is to seek perspective and support. 

Know what your “resilience needs” are, and then draw on them. For example, when I experience setbacks, I call a sibling to laugh about it. My resilience need is to tackle challenges with humor, and I know my brothers or sister will recognize the comedy in the situation and make me feel better.

Others might need someone who will just listen, be a shoulder to cry on, or become an advisor. 

Whatever your resilience needs are, identify who in your network can help you in that way, and then call on them at the right moments. Resilience is a team sport.

Mentally strong people don’t get worn down as much by the daily grind. 

Whether or not they realize it, they engage in a combination of gratitude and mindfulness — a practice I call grindfulness. It means being present and mindful enough in daily life to notice the details and show gratitude for the positive aspects of whatever grind you find yourself in. 

For example, say you’re having a tough morning at work. You’re answering a string of emails that came in overnight, and you’re frustrated. But you stop to marvel at the fact that you can type a few words, hit a button, and within seconds, your thoughts are transmitted to someone halfway across the world. Amazing. 

Your appreciation for this mundane detail lifts your spirits just a little, helping your mood. That’s grindfulness. 

Mentally strong people recognize when to let go of preconceived notions. They know when to drop points of view and ideas that are no longer relevant or useful to them. They identify and ditch bad habits that prevent them from moving forward productively. They regularly challenge their assumptions. 

In short, they know they sometimes need to unlearn in order to learn. 

Start by identifying and exchanging your limiting beliefs. What unhelpful stories do you tell yourself that have become ingrained? What unwarranted labels are you applying? 

For instance, you might label yourself as less talented than your peers and tell yourself: “I’m not good enough to get promoted.” Replace those limiting beliefs with empowering beliefs like, “I have all the skills needed to get promoted.”

It takes mental strength to consistently be supportive of others, especially in the face of negativity, when others are doing the easy thing and jumping on the “Complain Train.” 

Even better than generic encouragement or positivity is informed encouragement, which is when you give praise or positive reinforcement that is specific in nature. Doing so shows you took the time and care to indicate exactly what deserves praise and why, making your words feel more authentic and meaningful.

In times of change, you can act like change is something bad that causes pain and requires unwanted effort — like it’s something happening to you. 

Mentally strong people, on the other hand, see change as something positive, a jumping off point that can improve personal and professional fortunes — like it’s something that happens for you. 

You can choose to see change as a personal software upgrade, a catalyst for growth, and another opportunity to exercise your mental strength muscles.  

Scott Mautz is a popular speaker, trainer, and LinkedIn Learning instructor. He’s a former senior executive of Procter & Gamble, where he ran several of the company’s largest multi-billion-dollar businesses. He is the author of ”The Mentally Strong Leader: Build the Habits to Productively Regulate Your Emotions, Thoughts, and Behaviors.” Follow him on LinkedIn.

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Sarah and Jamie McCauley are landlords, YouTubers, Walmart pallet flippers, eBay resellers and Amazon product reviewers — and those are just their active streams of income.

The McCauleys make their money by researching what makes side hustles profitable, testing them and teaching others how to do the same on YouTube. The Grand Rapids, Michigan-based couple earned nearly $140,000 from eight streams of income last year, according to documents reviewed by CNBC Make It.

They’re particularly good at two types of gigs, they say: anything involving real estate and their YouTube channel itself, where they share their side hustle exploits with at least 146,000 subscribers.

“If you’re looking to just make some extra money on the side, maybe pay off a credit card debt or pay for a vacation, I think that is doable for nearly everybody,” says Jamie.

DON’T MISS: The ultimate guide to earning passive income online

The McCauleys are part of a side hustle revolution, a growing number of Americans who supplement income with multiple jobs. More U.S adults — about 39%, according to Bankrate — have side hustles today than ever before, whether out of necessity, precaution or a desire to increase their earning power.

Ease of starting is at an all-time high: Platforms like Amazon, Airbnb and Fiverr offer instant access to paying customers. But with competition also rising, it’s hard to build a side hustle that regularly brings in revenue.

Make It spoke with a selection of Americans with successful side hustles to learn how they built their businesses, and used them to fund a wide variety of financial goals. Every respondent highlighted four common traits that helped drive their success:

No matter what you sell, you need people willing to buy it. Jenny Woo says her side hustle is successful for a simple reason: She researches her audiences intensely, and tailors her products specifically to them.

Woo is an adjunct lecturer at the University of California, Irvine, a freelance business consultant and the teacher of an online course about emotional intelligence. Her one-woman side hustle, called Mind Brain Emotion, sells 12 different emotional intelligence-themed card games.

It brought in $1.71 million on Amazon last year, according to documents reviewed by Make It.

Woo’s first deck of cards, “52 Essential Conversations,” was tailored toward parents who — like her — wanted to connect with their kids and build their emotional intelligence skills. She joined parenting Facebook groups and observed users’ posting, commenting and liking habits, she says.

After selling $10,000 worth of the game in a 2018 Kickstarter campaign, Woo kept researching. She conducted a survey of her consumers, and learned that “overwhelmed” teachers looking to support children’s social and emotional development made up a significant portion of her audience, she says.

Her second deck, “52 Essential Relationship Skills,” was built for those teachers. It didn’t sell as well as her first deck, but it taught Woo that she could broaden, and combine, her audiences.

Woo applied that lesson to her third game, “52 Coping Skills.” She started with her own experiences working with college students during the Covid-19 pandemic and combined it with her continued research on teachers and parents, she says.

It’s now Mind Brain Emotion’s top-selling game, says Woo.

Woo sells on Amazon, which has a broad reach, to collectively rope in Mind Brain Emotion’s hyper-specific audiences. Tim Riegel’s products have a more singular customer base, so he sells on Etsy, a marketplace known largely for homemade and handmade goods.

Riegel, a full-time general manager at a sheltered workshop, makes firepits from recycled tank ends in Lamar, Missouri, and sells them under the name Mozark Fire Pits. His average product weighs 225 pounds, and sells for $950.

Mozark Fire Pits brought in approximately $202,000 on Etsy last year, according to documents reviewed by Make It. Riegel maintains a 40% profit margin, he says.

Riegel chose Etsy over platforms like Amazon, Wayfair and Overstock because it felt more user-friendly, and a better fit for his personalized products, he says. He also sells on Facebook Marketplace, which costs him more in advertising — but less in shipping costs for customers within a 200-mile radius, he adds.

That kind of platform analysis is valuable, no matter what kind of side hustle you run.

If you sell a service, instead of a good, you might consider platforms like Fiverr and Upwork — popular among photo editors, marketing writers and voiceover artists — or Taskrabbit, known for labor-intensive side hustles like cleaning or repair work.

Or, opt out of those platforms entirely. If your gig is something that many other people also do, try finding marketplaces with more narrow niches like Contently, Skyword or ServiceScape, recommends side hustle expert Kathy Kristof.

“One of the problems I see with a lot of freelancers is that they go to the best-known online platforms … and those platforms are so saturated with people who have been there for, often, decades,” says Kristof, whose blog SideHusl has reviewed more than 500 different side gigs.

No matter your platform, you’ll need to stand out. A good listing can help: clear and concise, written for your intended audience, free of typos, with high-quality graphics and some search engine optimization (SEO).

Becky Powell, a kindergarten teacher based in Beaverton, Oregon, has a side hustle selling worksheets for other educators on an online platform called Teachers Pay Teachers. Many of her worksheets focus on her personal specialty, teaching children sight-reading skills.

Her side hustle didn’t take off until she embraced SEO. When she uploaded her first worksheets, she titled them, “Creating sight words with pattern blocks.” Sales slowly trickled in.

Her husband Jerome, who has a business background, suggested a simpler title, like “Hands-on sight words.” The sight-reading worksheets quickly became her bestselling products, Powell says.

Powell’s store brought in $125,500 in 2022 revenue, according to documents reviewed by Make It. Her husband also sells worksheets on the platform, and they’ve used their combined earnings to fund vacations and pay down their mortgage and student loans, Powell says.

“You have to have passion and knowledge,” she says. “You also have to have a business sense [and understand] SEO.”

Once you gain enough customers, work to turn your sales into positive reviews, so you appear higher in platforms’ search results, Kristof advises. Customer service, prompt shipping and quality control can usually earn you a good online reputation.

The McCauleys have a rule for their ever-changing collection of side hustles: “You either have to be one of the first to get there, or your approach has to be very unique and different to be successful,” Sarah says.

But being first or unique doesn’t guarantee long-term success. In 2020, the couple was early to a side hustle trend: pallet flipping. At local warehouses, they’d buy pallets of returned goods from Amazon, Walmart or Target. They’d unbox the pallets, discover their contents and resell the items for a hopeful profit.

From December 2020 to December 2022, the McCauleys made about $19,500 in pallet-flipping profits, they estimate. Their most popular unboxing YouTube video got 5.4 million viewers, translating to an additional $30,000 in advertising revenue, says Jamie.

Last year, more Americans hopped on the pallet-flipping trend. Pallet prices rose, resale values dropped and a slew of unboxing videos diluted the McCauleys’ viewership. “The pallets became not really worth our time … from the standpoint of time over money,” says Sarah.

Four years ago, the McCauleys would’ve simply moved onto their next side hustle. Now, they’re feeling the strain of constantly building new gigs from scratch, and starting to reorganize their income streams into a smaller number of longer-term projects.

Instead of flipping their current home renovation project in Northern Michigan for a profit, for example — something they’ve done multiple times — they’ll keep it as their own vacation house and part-time Airbnb rental, they say.

“We always knew [side hustling] was going to have an expiration date,” says Jamie. “It’s a young person’s game, to always be looking for what’s next.”

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Almost 60% of the caloric intake of the average American diet is coming from ultra-processed foods, according to a 2017 paper published in the journal Population Health Metrics — and that’s concerning to health experts.

“Ultra-processed foods contain ingredients that we generally wouldn’t find in our kitchen, and they often contain high amounts of sugar and salt,” says Jinan Banna, registered dietitian and professor of nutrition at the University of Hawaii.

“They may also contain additives, and they often are stripped of their nutritional values. So they may have very little vitamins and minerals [and] fiber.”

Eating ultra-processed foods often can lead to a higher risk of developing health conditions like dementia, type 2 diabetes and heart disease, according to doctors in the American Medical Association.

That’s why Banna limits her consumption of ultra-processed foods and encourages you to do the same. Here’s the highly processed food that she never consumes.

“Some [ultra-processed foods] I would never consume, such as soda,” Banna tells CNBC Make It.

“Soda doesn’t have any nutritional value other than just calories in the form of sugar. So they’re empty calories, which don’t give us any of the nutrients that we need.”

When you drink soda, it is digested very quickly and can cause you to feel hungry, she adds, which can lead you to eat more food than you planned to.

Instead of soda, Banna opts for different types of tea and water, still or sparkling.

“Sometimes I drink a cold hibiscus tea. Plain water, of course, is a great alternative,” she says. “Even coffee can be an option, of course, consumed in moderation.”

A recent preliminary study that was presented last week at a meeting held annually for the American Society for Nutrition took a close look at dietary data collected in 1995 from more than 500,000 Americans between the ages of 50 and 71. The data was used to determine if there were connections between dietary choices and mortality rates over the span of almost 30 years.

Out of 124 foods, ultra-processed drinks was the No. 1 food that people who had the highest intake of ultra-processed foods consumed.

“Diet soft drinks were the key contributor to ultra-processed food consumption. The second one was sugary soft drinks,” the study’s lead author Erikka Loftfield told CNN.

Beverages make up a significant portion of dietary intake. So, these types of drinks — like diet sodas and energy drinks — are the processed food that people seem to consume more than others, Loftfield said.

The study also found that the lifespans of those who eat a diet high in ultra-processed foods may be shortened by over 10%, according to CNN.

As a rule of thumb, Banna recommends using the 5/20 method when checking the nutrition labels on the foods you eat.

“You can use the daily value,” she says. “That’s an easy way to know whether the food is generally high or low in a particular nutrient.”

Check the daily value percentages of specific nutrients like sodium, sugars or saturated fat, Banna suggests.

“The idea is, if [it’s] 5% or less, then the food is generally low in that particular nutrient. If 20% or more, you can consider the food high [in the nutrient],” she says.

“So that’s just a quick way to glance at the label and know if a food contains a little bit or a lot.”

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Of all the things I fear — spiders, needles, rejection — regrets take the cake. I have a deep-rooted fear of getting to the end and feeling woefully disappointed — not so much by the life I lived but by the life I didn’t live.

In many ways, I have my mother to thank for waking me up and helping me course-correct. She died at 58 with a litany of regrets. After losing her, I was gripped by the fear of dying with my own laundry list of “if onlys.” 

I committed to live a regret-free life or die trying. Now I’m hell-bent on helping us all make the most of our time while we’re lucky enough to be above ground. I want us to live regret-free lives we can feel proud of. 

That’s why I left my job as a corporate executive to become a “stop squandering your life” speaker and coach. It’s why, while I was in the University of Pennsylvania’s Master of Applied Positive Psychology program, I wrote a 101-page thesis about “reflecting on mortality to inspire vitality and meaning in life.” And it’s why I recently published my book, “You Only Die Once: How to Make It to the End With No Regrets.”

As terrifying as regrets are, they can be useful, because they can motivate us to change our behavior and improve our lives. That is, they can help us after we simmer in the uncomfortable awareness of what could have been if we’d only made a way better decision.

We tend to value regret more than any of the negative emotions out there, studies show, because we understand its value and power.

There are two main categories of regrets you want to pay attention to:

1. Regrets of commission: These include things we did that we wish we hadn’t done. We tend to be able to rationalize regrets of commission through the softening of time.
2. Regrets of omission: These include the paths we didn’t take, the things we wish we’d done that we never did. Regrets of omission tend to haunt us. 

Also known as hot regrets, regrets of commission tend to feel intense at first. They’re often stupid things we do that make us burn in the short run with shame, guilt, or remorse, and then cool off over time.

Here’s a true-crime sampler from my clients and workshop attendees: 

• “Being mean to Kandy on the schoolyard in sixth grade” 
• “Having an affair” 
• “Telling that client what I really thought of them” 
• “Getting a DUI” 
• “Leaving my vintage baseball card collection at home for my mother to later throw out” 
• “Giving Tom the finger after quitting in a huff” 
• “Eating three-day-old sushi” 

Also known as wistful regrets, regrets of omission can torment us until the end of time. 

Real-life client examples include: 

• “Not backpacking across Europe after college” 
• “Not running that marathon”
• “Not finishing law school” 
• “Not fixing my relationship with my brother” 
• “Not writing that children’s book”
• “Not ordering desserts just for myself; I wish I’d had more pieces of cake all to myself” 
• “Not telling my first crush I loved him”

Regrets of omission plague us mostly because these are paths not taken. They shine a glaring spotlight on the chasm between our actual selves and the person we’ve imagined as our ideal self, one that could make our dreams come true.

Anticipating our regrets before they come to fruition — or what I call our “pre-grets” — gives us a chance to live a life that feels right. 

In my book, I share several exercises, assessments, and tips designed to help you identify your pre-grets and figure out how to use them to your advantage. Here’s one way to start: 

• Get comfy in bed. Yes, for real — recline your body and take a deep breath. Imagine you’re lying on your deathbed. You’re not in pain. You feel lucid and at peace. You’re near the end and reflecting back on your life. Start to zero in on your regrets of omission — not the things you did do but rather the things you didn’t do. 
• Make a list of what comes up for you.
• Circle the entries that make your heart beat fast, or make it ache or skip a beat. Any heart-related reaction is a good indication that this one matters. 
• Pay close attention to the pre-grets that want to hide on the page because they’re fragile and afraid to be exposed. Perhaps you feel fear of failure or rejection or ridicule. That’s a sign that it’s important to protect and be kind to those dreams.
• Start brainstorming ways to take even one step forward. Better yet, write one down right now. 

An unflinching awareness of your pre-grets can change the trajectory of your life.

That’s because we don’t have to continue down the paths we’re on and resign ourselves to regrets of omission. We don’t have to merely imagine the paths not taken.

We can go down entirely different paths if we choose. We just have to recognize what matters deeply to us and take action.

Jodi Wellman is a former corporate executive turned executive coach. She has a master’s in applied positive psychology from the University of Pennsylvania, where she is an instructor in the master’s program and a trainer in the world-renowned Penn Resilience Program. She runs her own business, Four Thousand Mondays, and is the author of ”You Only Die Once: How to Make It to the End With No Regrets.”

Want to be a successful, confident communicator? Take CNBC’s new online course Become an Effective Communicator: Master Public Speaking. We’ll teach you how to speak clearly and confidently, calm your nerves, what to say and not say, and body language techniques to make a great first impression. Sign up today and use code EARLYBIRD for an introductory discount of 30% off through July 10, 2024.

Excerpt adapted from ”You Only Die Once: How to Make It to the End With No Regrets″ by Jodi Wellman. Copyright © 2024. Reprinted with permission of Voracious, an imprint of Little, Brown and Company. All rights reserved.

Last year, a resale ticket to Taylor Swift’s record-breaking Eras Tour cost an average of $2,183. That was part of a larger pattern: From 2019 to 2023, consumers faced a 95% spike in concert resale prices.

Some people found ways to benefit. One reseller I read about reported making a $20,000 profit. But fans like me had to deal with sticker shock after a Ticketmaster fiasco made purchasing face-value tickets nearly impossible.

While scanning resale sites for her New York shows in May 2023, I found an obstructed-view seat at the top of the stadium for about $1,000. It seemed like a bargain compared to another ticket closer to the stage, listed at more than $15,000.

For a brief, particularly delusional moment, I considered spending a thousand dollars. I had never considered spending so much on live music before, but the Eras Tour featured songs spanning her entire career. It promised to unlock too much nostalgia to pass up.

I had been listening to Taylor Swift since I was about 14 years old and leaned on her music as I grew up. Swift crystallized the sometimes heartbreaking and ecstatic moments of girlhood with catchy, relatable songs. At the age of 30, I wanted to relive the eras of my youth alongside tens of thousands of likeminded people.

Thankfully, I snapped out of it and stayed home. I was disappointed, and had to stop watching tour content online as it added salt to the wound, but I was glad I saved the money, and hopeful I would still somehow get another chance.

A few months later, Taylor Swift, now officially a billionaire, announced a European leg of her 2024 tour.

After Ticketmaster failed me again, I turned to StubHub in July 2023 and found floor tickets to her Paris show for about $400 each. I bought two: One for me, and one for a friend and fellow co-conspirator who quickly reimbursed me.

I paid about $230 above face-value, which was still less than the unbelievable amount I would have had to pay in the States. 

The concert became the centerpiece of a week-long vacation in Europe. I started the week in Barcelona and ended it in Paris. I spent about $620 on flights, split a hotel with my partner in Barcelona before he took off for Morocco, and saved money on a hotel in Paris by staying with a friend.

For months, I worried my resale tickets could be a scam, but I proceeded with booking flights and making travel plans. I figured if it didn’t work out in the end, I would still get to see both Spain and France, and there’s nothing bad about that. 

I arrived in Paris the day before the show and found out another friend from New York was in town. She didn’t have plans to go to the concert. We gathered over a spread of charcuterie and throwback Taylor Swift tunes — and by the end of the night she had purchased a resale floor ticket for the equivalent of $245.

In May, my two friends and I boarded the train to La Défense Arena in Paris. Many Americans, I learned, were making the same journey. We met a mother from New York who checked her daughter out from school the day before, surprising her with tickets and a flight across the Atlantic. 

In a crowd of glitter and friendship bracelets, we made our way to the entrance of the stadium. Our tickets were scanned and finally, we were in.

We spent the next several hours dancing, singing, and swaying with the crowd. We savored the show, indulging in music that transported us to a past decade.

My friend said we had reached “peak girlhood.”

For less money than Taylor Swift tickets were re-selling for in the U.S., I was able to eat tapas in Barcelona’s Gothic Quarter and dine on sugar-dusted crepes with a view of the Eiffel Tower. I spent quality time with people I love and wandered through beautiful cities.   

With their sequined dresses and shiny cowboy boots, the Taylor Swift fans that crashed into Paris that weekend were easy to spot. On the metro, in gardens and at bistros throughout the city, strangers gushed with excitement.

Finally, we got to be part of the cultural phenomenon — in Paris, of all places.

The day after I saw the show, I spotted two bejeweled tourists hopping into a taxi and guessed they too were heading to see the tour. I told them to have the best time. When they smiled back and thanked me, I detected an American accent. I hope they also saved some money last year and spent it on a European getaway instead.

Want to stop worrying about money? Sign up for CNBC’s new online course Achieve Financial Wellness: Be Happier, Wealthier & More Financially Secure. We’ll teach you the psychology of money, how to manage your stress and create healthy habits, and simple ways to boost your savings, get out of debt and invest for the future. Start today and use code EARLYBIRD for an introductory discount of 30% off through September 2, 2024.

Plus, sign up for CNBC Make It’s newsletter to get tips and tricks for success at work, with money and in life.