Today Mark Cuban is 61 and worth over $4 billion, according to Forbes. But during his 20s, Cuban was often broke.
Still, despite having to hustle to make ends meet when he was younger, Cuban would tell his 20-year-old self: "Don't change a thing," he tweeted in October.
"Don't stress. Don't change anything. Have fun," Cuban told Business Insider in 2015.
"You don't have to know what you're gonna be when you grow up. You don't have to have answers. You don't have to have the perfect major. You don't have to pick the perfect job. You're allowed to f--- up."
And when reflecting on his college years, he told Business Insider: "When you graduate, go out and get that job where you get paid to learn."
Cuban didn't have a set path. He started college at the University of Pittsburgh but transferred to Indiana University after his freshman year. Without ever seeing the campus, he picked Indiana's Kelley School of Business because it had the cheapest tuition among the top 10 business programs at the time.
In order to pay tuition during his college years, Cuban got creative: He sent out a chain letter that asked recipients to submit money, taught disco lessons to sorority girls and worked at a bar on campus.
"I got paid $25 an hour back then to teach [disco] dancing to sororities," Cuban said on a podcast with Jim Rome in April. "It was the best job ever."
In 1981, just before graduating college, Cuban used the money he'd saved from his various side jobs to open a pub with a friend in Bloomington, Indiana. However, it eventually shut down and Cuban was forced to move to Texas.
At 23, "I left with $60, hole in my floorboard, case of oil in the trunk & a floor to sleep on in Dallas," Cuban tweeted in July 2017.
He moved into a $600-a-month three-bedroom apartment with five other guys. Cuban had no money and student loan debt, but was still having "a whole lot of fun," he said.
"I ... loved my life when I was eating mustard and ketchup sandwiches and sleeping on the floor of a three bedroom apartment that housed me and five buddies," Cuban said in an October 2008 blog.
Cuban quit his first job after college graduation (at Mellon Bank) and then was fired from a computer software company. But the experience working in tech led him to start his own company, MicroSolutions.
In 1990, he sold his company MicroSolutions to CompuServe for $6 million. Five years later, he and a friend, Todd Wagner, started Broadcast.com, which was later acquired by Yahoo in 1999 for $5.7 billion in stock.
Cuban is now a billionaire investor, owns the Dallas Mavericks basketball team (which he bought for $280 million in 2000) and is a star on ABC's "Shark Tank."
"I have a whole lot more fun now," he said in his blog. "It doesn't suck to be rich."
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Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank."