7 highly successful leaders share the top advice they wish they could go back and tell their younger selves

If I could send a letter to who I was a decade and a half ago, it would say two things. First, find a mentor. Then solve bigger, more sophisticated problems so you can make more money and have a bigger impact.

Invest in more mentors right away. They may even be free, though you'll need to put in some sweat equity. For example, when I was a personal trainer, one of my clients mentored me while I trained him in the gym. I got a lot of exposure to entrepreneurial lessons I would not have access to otherwise. Get coaching, join masterminds, and pay for a mentor if you must. Go to events where you can be mentored by those who are miles ahead of you and have done what you want to achieve. Collapse time and get an outcome faster, with less frustration and less money.

Then solve bigger and more sophisticated problems for people, because that's how you make more money and have more of an impact on others' lives.

— Bedros Keuilian, founder of Fit Body Boot Camp, author of "Man Up," and host of "Empire Podcast Show." Read how Bedros built his dream life and connect with Bedros on Instagram, Facebook, and YouTube.

If I could write a letter to my 21-year-old self, this is what it would say: First, stop drinking so much. Develop sober social skills. Second, shed your introverted excuses and learn to sell in person, face-to-face. This is one of the most important skills that anyone can develop at any age. The sooner you use it, the faster you'll grow rich, find the love of your life, be a better conversationalist, and master your sober social skills.

Third, stop working for money and start working for experience. Find the most successful person who shares your morals and ethics, offer value so they agree to take you on as an apprentice, and never, ever let them down. These might be the three greatest investments you ever make in your life.

— Craig Ballantyne, owner of Early to Rise and creator of The Perfect Day Formula and Social Story Selling System; author of the WSJ best-seller "Unstoppable"; read how Craig overcame entrepreneurial anxiety. Follow Craig on Instagram, Facebook, and LinkedIn.

Looking back, I would have grown my business far faster if I had mastered two key things. First is a networking mindset. The network I've developed in the past three or four years has been invaluable in growing my business from six figures to multiple seven figures. This has been so pivotal that I've joined several masterminds costing over $100,000 each purely to develop a stronger network and keep growing it.

The other advice I would give myself is to master (or at least understand) the fundamentals of marketing, like direct response marketing, copywriting, Facebook advertising, and sales funnels. With networking and marketing alone, I believe anyone can grow a lucrative, impactful, and successful business.

— Rudy Mawer, founder and CEO of ROI Machines and RudyMawer.com; Facebook marketing and ad expert, who built a multimillion-dollar business by age 26. Connect with Rudy on Instagram.

I wish I could write a letter to my 19-year-old self when I was a health and fitness coach who wanted to do more. I spent the better part of a year asking myself whether I was allowed to and whether it would be accepted. Even once I did move forward, I still held myself back.

To that girl, I would say: Your aligned life is available to you today. You don't need to wait. Holding back from what you feel guided to do will make things harder. So make those leaps and put yourself out there, completely and unapologetically.

The world needs every bit of your uniqueness; so do what you feel called to do — whatever that is and however it looks. Say what you want to say, even if it shocks everyone. Stop speaking to the masses, and focus on speaking to the highest version of the soul-led clients you were born to lead. What you feel inside is real, and you need to trust your intuition. Your path hasn't been created yet; you're the one who has to do it. The sooner you start, the better!

—  Katrina Ruth, founder and CEO of "The Katrina Ruth Show," a multimillion-dollar online coaching business for entrepreneurs. Connect with Katrina on Facebook and YouTube.

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Today, I truly understand the law of reciprocity, but I didn't when I was younger. If I could slip a letter to my 25-year-old self, I would explain the advantages of creating value for the people you want to learn from.

If I could go back to my first day selling luxury homes or my first day building my real estate business, I would identify the top salespeople and managers I admired the most. Then I would cover weekends or showings for them when they needed extra help. By getting the right people vested in you, you compress time and create a successful career. Be a champion for others, and they will come through for you.

— Keri Shull, founder of the Keri Shull Team, which has sold over $2 billion in properties; co-founder of real estate coaching business HyperFast Agent; named one of America's Best Real Estate Agents by REAL Trends. Connect with Keri on Facebook.

I would send a letter to my 18-year-old self, who was just two years away from becoming homeless on an island thousands of miles away from his family. I would encourage him to find his passion and pursue it. When you're passionate, you're driven to succeed and less likely to burn out. At 18, you're young, energetic, and perfectly placed to chase your dreams. Find a calling that fulfills you, be resilient, and never quit.

Take calculated risks — and act on them. This leads to self-discovery and self-confidence. If you fail, you learn from the experience and move on to the next challenge. Gain new knowledge and skills by reaching outside your comfort zone. Set goals to stay motivated. They don't have to be huge, but write them down and find time to work toward them every day.

Finally, give to others without expecting anything in return. Focus on the impact you're making on the other person, and the universe will reward you tenfold. This is how you build a strong foundation for success.

— Andres Pira, real estate developer, founder and CEO of Blue Horizon Developments, and author of "Homeless to Billionaire: The 18 Principles of Wealth Attraction and Creating Unlimited Opportunity." Follow Andres on Facebook, Instagram, and YouTube.

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