Here's Why so Many Successful Entrepreneurs Got Their Start in SalesThe persistence, discipline and creativity required for making sales is the perfect cocktail for success in founding a business.

Everyone has an opinion about salespeople, and it's often negative. But according to a 2017 survey conducted by Heidrick & Struggles,nearly 15 percentof Fortune 500 CEOs got their starts in sales. Say what you will about the oftentimes incorrectly portrayed "pushy" salesperson but, along with a few other unique strengths, their persistence is exactly what makes them successful.

It's also why you -- if you have ambitions to be the next Mark Cuban, Elon Musk or Oprah Winfrey -- should learn to sell.

One of the first truths you'll learn about entrepreneurship is that you're 100 percent responsible for your success or failure. It can be hard to adjust at first, but selling products or services to strangers and living off commission is a perpetual training ground for that very lesson. Besides that, experience in the sales world helps you develop several skills that you'll need to overcome the challenges of being your own boss.

Planning to launch the next great Kickstarter campaign or turn your startup weekend idea into a part-time business? Consider making your mark in the sales world first.

Related:5 Jobs Every Entrepreneur Should Work Before Building a Business

A training ground for great entrepreneurship.

All of my beginner jobs, from washing dishes to painting to working as a prep cook, paid by the hour rather than by the quality and amount of work I put in. My co-workers and I were just trading time for money. We had very little incentive to do well. When I finally gathered the courage to join my first sales team -- even though multiple family members told me I wasn't cut out for it -- I experienced the power of performance-based income. I never measured success the same way again.

I learned to confront and shrug off rejection. I mastered the art of a true work ethic. I learned to close a deal, to persuade people that my solution was the best for their problems.

Here's a breakdown of those skills and how they can help you navigate the road to successful entrepreneurship:

1. Eat the frog first.

Early on in my sales career, I would stare at a list of potential customers I was reluctant to call. But procrastinators don't make money, and my manager insisted that I learn to eat the frog first.

The lesson was this: tackle the most important and dreaded task, regardless of whether I felt like doing it. I also had to do it with enthusiasm. In sales, rejection, defeat and disappointment are par for the course. Entrepreneurship is the same. Develop the discipline of facing it head on, and it'll lose all its power over you. If you can master this habit as a salesperson for another company, you will have a much easier time doing it at your own.

Eating the frog means waking up earlier than your friends with "normal" jobs. It's no secret that the most successful people start their days a lot earlier and work a lot harder than less successful people. Ever hear ofHal Elrod's"miracle morning?" In hismust-readbook "The Miracle Morning," Elrod argues that willing yourself to get out of bed early and get into a routine will help you build the life of your dreams. Victory in the business world goes to the stubborn and persistent, after all.

Related:Do You Sleep More Than Elon Musk, Mark Cuban, Sheryl Sandberg and Other Leaders?

2. Create opportunity by doing, not just wanting.

My first commission-based paycheck was for more than $700. Not bad for a 19-year-old in his first week at an entirely new gig. Before then, the biggest paycheck of my life had been for $300, and it required an overnight shift breaking down a banquet and scrubbing fossilized cheese off catering dishes. In that moment, I realized that the value I can produce wasn't limited by hours in the day. My resolve and imagination are all that matter.

Sales isn't a 9 a.m. to 5 p.m. commitment; neither is entrepreneurship. In fact, both can take as much as 10 to 14 hours per day, including the occasional weekend and holidays. Both positions are professions. They feel more like callings than mere jobs. People can get lost in them. And while I don't condone workaholism, starting and succeeding at anything requires hustle.

The 2015/2016 Global Entrepreneurship Monitor survey found that31 percentof surveyed entrepreneurs listed innovation and creativity as most important to their education. Sales, just like entrepreneurship, is a "You're only limited by yourself" career path. As soon as you start thinking about how much value you can add, you start to see opportunities for innovation everywhere. You start to think: "There should be an app for that," "This should be easier," or, if you're Elon Musk, "Humanity would be better served if ..."

3. Find your vehicle, and drive it relentlessly.

In my sales days, making 20 calls an hour was considered productive. If I wasn't feeling motivated, though, then it was OK to make only 15 calls, right? Wrong. Five calls might not seem like much, but 75 percent effort won't get you 100 percent results in your sales career or as an entrepreneur.

Once you find your "vehicle" -- the opportunity that you can't stop daydreaming about -- drive it relentlessly. Manifesting that vision requires the same principles as sales. Entrepreneurs who can't close a sale, finish a pitch, negotiate a deal or onboard talent won't last long in the marketplace; fortunately, this highly tactical skill and the emotional confidence to wield it can be learned through sales.

Related:3 Unconventional Sales Tactics That Will Close More Deals

For Xerox CEO Anne Mulcahy, for example, her entrepreneurial vision was making the printing giant profitable again. It requiredreinventing the entire strategy, making bold decisions and enduring a few sleepless nights, I'm sure. Those are the requirements to succeed. For me, it was the dream opportunity of starting my own brick-and-mortar Vector office, which required building a team that was just as driven as I was.

When I started in sales, I knew it would be different. And it was. What I didn't realize was just how well that experience would prepare me for my next big leap to entrepreneurship. Sure, not every successful entrepreneur has a sales background. But salespeople learn to exercise discipline, cultivate opportunities and drive those opportunities forward, and those qualities are critical for those of us determined to take on the challenges and possibilities of the entrepreneurial world.