A millionaire CEO who was once homeless says these are the 3 most important lessons he's ever learned

When Dave Sandoval was 17 years old he decided to move out.

"I couldn't live in a house without food anymore," he tells Business Insider. "I made myself homeless. I walked away, and it was a better life than the one I had."

Sandoval, now 53, has mostly good memories from his year as a vagabond - like sleeping on the beach and being the first person to catch a wave in the morning, or pretending to be drunk at parties so the hosts would offer him their couch for the night. "When you're that young, you're used to acting defiant," Sandoval says. "And making myself homeless was a way of proving to the world that I didn't need a home."

The carefree and entrepreneurial-minded man spent the next 35 years jumping from job to job. He worked at a bowling alley, sold stereos, fixed golf carts, worked at an oil factory, washed trucks, sold real estate, and eventually sold stocks. He got fired from every single one of those jobs, "not because I wasn't there on time, but because I kept telling the boss 'We could do this better or cheaper,'" Sandoval says.

In the early 90s, after hearing that his aunt died of multiple sclerosis because of the way she ate, Sandoval went to work for a Japanese pharmaceutical company to promote healthy living. However, he soon learned that the company was not in fact selling organic and unpasteurized products. "I said, 'Who the hell is going to do something just because it's right? Why does everything have to be driven by somebody's self interest?'" Sandoval says.

That's when he started making 100% pure products out of his home in 1994, and he now has 100 pharmacists and almost 30,000 salespeople around the world working for his company, Purium Health Products, which hit $47 million in revenue last year and is expecting to hit $75 million in revenue this year - a 276% growth in just three years.

He says there are three important lessons he's learned that have helped him get to where he is today: