Billionaire John Paul DeJoria describes the childhood lesson that helped him transition from being dirt poor to filthy rich

It's easy to see why John Paul Mitchell Systems hair care and Patrón tequila cofounder John Paul DeJoria likes to defend the American Dream - he embodies it.

Born in Los Angeles in 1944 to poor immigrant parents, DeJoria's life has been filled with rough patches. He spent time in a street gang as a boy, was homeless twice, was fired multiple times, worked as a janitor and salesman to stay afloat, and faced the prospect of losing everything on a business that seemed poised to fail.

Today, at age 70, he has an estimated net worth of $2.9 billion and is in charge of about 10 businesses and a foundation.

DeJoria tells Business Insider that transitioning from pauper to prince wasn't as overwhelming as one might expect. Instead, he says it was "very easy," thanks to a lesson his mother taught him as a child.

DeJoria was 38 years old when he first felt like he was on the path to wealth. After two years in business, John Paul Mitchell Systems had made a profit, and he and his late business partner Paul Mitchell could finally pay their bills on time and had $4,000 in dividends to split. "I knew, man, we had made it," he says.

"The biggest thing was I could sleep at night and not worry about not paying my bills the next day," DeJoria says. "Because that freaked me out."

As the wealth began seriously accumulating throughout the '80s and onward, he says the memories of everyone who helped him when he was at rock bottom kept him psychologically grounded.

"As the money came, I was so thankful and appreciative," he says. He didn't forget people like the actress Joanna Pettet, for example, who gave him a guest room to live in for two months when he was living in his car. Or the staff of the Freeway Cafe, who would provide him with extra portions of food when he lived on a couple dollars a day.

He made sure to return the favor to his benefactors, and remembered how he had felt before he had the privileges that come with wealth.

He remembers that as a young boy, his mom taught him that the family should give back even a little bit to those who had it worse than they did.

"At Christmas we might give a dime from the whole family to the Salvation Army. She would say, 'Boys, they need it more than we do.'"

DeJoria, of course, uses his money to make more of it, but he says that after he became successful he derived the most enjoyment from sharing his wealth.

"And that feeling, money can't buy," he says.