Here's the advice Jay Leno would give his 20-year-old self

Former host of "The Tonight Show" Jay Leno
NBC | Getty Images

If comedian and former host of NBC's "The Tonight Show" Jay Leno could do it all over, the 66 year old wouldn't change much.

If given the chance, he would tell his younger self, "Do exactly the same thing," he says. "Because every mistake you made will give you empathy for other people that make the same mistake."

Plus, "you learn a tremendous amount from the mistakes," says Leno, who now hosts CNBC's "Jay Leno's Garage."

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Billionaire entrepreneur Richard Branson agrees.

"Whether it is launching companies like Virgin Brides and Virgin Cola that fell flat on their face, making the wrong call on investments, or simply forgetting to return a call or send an email, I have made hundreds of mistakes," the Virgin Group founder writes.

"I'm sure I'll make many more this year, and learn valuable lessons from every error. Anybody who tells you they don't make mistakes has just made one."

While success stories tend to steal the headlines, there are inevitably a handful of mistakes that happen behind the scenes, Branson says: "Experiencing setbacks is part of the DNA of every successful entrepreneur, and I am no exception."

What's more, failure keeps you humble, Leno says: "People who don't make mistakes get sort of cocky and start to think of themselves as better than others.

"So, yeah, I would make the same mistakes all over again."

CNBC's "Jay Leno's Garage" airs Wednesdays at 10 p.m. ET.

Jay Leno has no debt thanks in large part to abiding by this one rule