The end of the year is typically a time to reflect, reset and prepare for the year ahead. It can also be an opportunity to celebrate your good fortune, and to consider what might have been.
Self-made billionaire Mark Cuban, for example, knows how lucky he is. But if the "Shark Tank" investor and Dallas Mavericks owner lost everything overnight, Cuban believes he could do it all again.
His first step would be to go out and get two gigs.
"I would get a job as a bartender at night and a sales job during the day, and I would start working," Cuban said in an episode of the podcast "How I Built This" last December.
If he had to start all over again tomorrow, he's not sure he could become a billionaire again. "To be a billionaire, you have got to get lucky," Cuban said.
But he's certain that he could turn seven figures. "Could I become a multimillionaire again? I have no doubt."
Cuban learned how to be a good salesman early on in his life. In his teens he was selling baseball cards and stamps. One of his first jobs out of college was selling computers and software. "I was the best," he said. "I crushed it."
Could I become a multi-millionaire again? I have no doubt.Mark Cubanentrepreneur
Naturally, if forced to start over, he would draw on that talent.
"Knowing what my sales skills are and the products that I am able to sell, I think I could find a job selling a product that had enough commissions or rewards for me," said Cuban.
From there, Cuban would get enough money in the bank to be able to start his own business, and the rest would be history.
Cuban isn't the only one to contemplate his ruin. Here's what other self-made millionaires and billionaires say they'd do if they had to start over again tomorrow:
Bill Gates would learn a new field, like AI
The Microsoft co-founder 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 would keep investing
The Berkshire Hathaway CEO would choose to be an investor again, in part because he finds it so enjoyable. "I had fun when I was in my 20s, my 30s, 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 would start another business
If the billionaire Virgin Group founder 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 would sell cars
The Camping World CEO and star of CNBC's "" 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 in the morning and work 'til 10 at night," says Lemonis. "And I enjoy it."
This is an updated version of a previously published article.
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