"It doesn't matter how many times you f--- up," Cuban said on Barstool Sports' "Pardon My Take" podcast on Feb. 4. "You only gotta be right once. Then everybody tells you how lucky you are."
Cuban said people only focus on his big successes: first selling start-up MicroSolutions in 1990 to CompuServe for $6 million, and nine years later selling Broadcast.com to Yahoo for $5.7 billion in stock. They never talk about the hiccups that came first.
Cuban's first fail happened while he was still in college.
"I started a bar, Motley's Pub, when I wasn't even of legal drinking age the summer before my senior year at Indiana University," he wrote in his book "How to Win at the Sport of Business: If I Can Do It, You Can Do It."
The campus bar was cited for having underage patrons and was shut down, according to the Dallas Morning News.
"No one really asks me how it turned out. It was great until we got busted for letting a 16-year-old win a wet T-shirt contest. (I swear I checked her ID, and it was good!)," he wrote in "How to Win at the Sport of Business."
After graduating from Indiana University in 1981, Cuban had "quit or been fired from three straight jobs," he said on an episode of ABC's "Shark Tank."
At 22, Cuban moved back to his hometown, Pittsburgh, got a job at Mellon Bank and ultimately quit because he didn't like the CEO, he wrote in a piece for Forbes in 2013. He also worked for a TV repair franchise Tronics 2000, but that job didn't work out either.
Then Cuban moved to Texas and tried to start a business selling powdered milk, which failed. After, Cuban landed a sales gig at computer company Your Business Software, but got fired for closing a deal without approval from the CEO (another fail). But getting fired led him to start his own computer systems company, MicroSolutions.
While living in Dallas, Cuban slept on the floor of a three-bedroom apartment where he lived with six other guys. He often came home to the lights turned off and he had his credit cards cut as he struggled to make ends meet, he said during an Oxford Union Q&A in 2017.
"No one really asks me about my adventures working for Mellon Bank, or Tronics 2000, or trying to start a business selling powdered milk (it was cheaper by the gallon, and I thought it tasted good enough)," he wrote in his book "How to Win at the Sport of Business."
"They don't ask me about getting fired from my job at Your Business Software for wanting to close a sale rather than open up the store. No one ever asks me about what it was like when I started MicroSolutions or how I used to count the months I was in business, hoping to outlast my previous endeavors and make this one a success."
But according to Cuban, all that matters is one success.
"It doesn't matter how many times you strike out," he wrote in his book. "To be a success, you only have to be right once. One single time and you are set for life."
Today, Cuban is worth $4.1 billion, according to Forbes.
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Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank."