Individuals who have achieved tremendous levels of success, fame and fortune have put in lots of hard work over the years, but most of them will admit they've also gotten lucky along the way.
Those moments of good fortune are hard to quantify and could be impossible to replicate. Could Bill Gates become Bill Gates again, if he had to? Could Mark Cuban become Mark Cuban?
Below, five exceedingly successful entrepreneurs reflect on what they would do if they lost everything or had to start over.
Mark Cuban
Owner of the Dallas Mavericks and star of ABC's "Shark Tank"
"I would get a job as a bartender at night and a sales job during the day, and I would start working," says Cuban.
He isn't sure he could become a billionaire again. "To be a billionaire, you have got to get lucky," Cuban says. Still, he's confident in his abilities. "Could I become a multimillionaire again? I have no doubt."
Bill Gates
Co-founder of Microsoft, co-chair of The Bill and Melinda Gates Foundation
Gates would not focus entirely on earning and instead would devote himself to a field he finds fascinating, such as artificial intelligence, energy or biology. "The work in artificial intelligence today is at a really profound level," says Gates. "It is going to be phenomenal, so anything connected with that I think would be an exciting lifetime career."
Warren Buffett
CEO of Berkshire Hathaway
Buffett would choose to be an investor again, in part because he finds it so enjoyable. "I had fun when I was in my twenties, my thirties, and now I am 86 and I am having fun," he says. Also, he focused on what he was good at: "I would be a failure at anything else, probably."
Richard Branson
Founder of the Virgin Group
If the 66-year-old billionaire were to wake up and be 20 again, he would welcome the challenge of once again becoming successful.
"I'd quite like to go back and plot out my life all over again — dreaming big dreams," says Branson. "The benefits of dreaming far outweigh the perceived risks, because the value of dreaming isn't just measured by the outcome, but the inspiration that comes from journey of achieving the dream."
Marcus Lemonis
Star of CNBC's "The Profit" and "The Partner"
Lemonis wouldn't make significant changes, either. He got rich in the automotive industry and, he says, "If I lost everything today and I had to start over, I would go sell cars.
"Because I'm working with somebody else's inventory, I control my own pay plan. I control my schedule. I can get up at 5:00 in the morning and work 'til 10:00 at night," says Lemonis. "And I enjoy it."