Mark Cuban says this 1 huge failure led him toward multibillion dollar career path

In Mark Cuban's eyes, every job he's ever held — even in his high school and college years — has contributed to his massive career success.

The Dallas Mavericks owner, who's now worth an estimated $4.1 billion, took on several bizarre "side hustles" in his younger days. But his huge failure at one of these jobs, in particular, he says gave him the push he needed to take a huge risk — and it paid off.

The 60-year-old "Shark Tank" star revealed he got the boot from a post-graduation job during the World Leaders Forum at Judson University in Elgin, Illinois, on Tuesday.

"I was fired from a software store, living with five other guys, and feeling stressed and stuck. I wanted to control my destiny, and starting my own company was the only way to do that," recalled Cuban, referring to his first business MicroSolutions, according to Patch.com.

He explained that he was let go for closing a sale at the store instead of cleaning.

The billionaire investor has previously admitted he had quit or been fired on at least three separate occasions before he started MicroSolutions. He sold the software company for $6 million in 1990, Dallas News reports. He then helped lead Internet radio company Broadcast.com, an Internet radio company that was acquired by Yahoo! in 1999 for $5.7 billion in stock.

Cuban has a classic rags-to-riches story.

After graduating from Indiana University in 1981, Cuban recalls only having around $60 in his pocket.

"I'm just a grinder. I always have been. I didn't get a small million dollar loan from anybody."

- Mark Cuban

"I'm just a grinder. I always have been. I didn't get a small million dollar loan from anybody," Cuban reportedly joked on Tuesday.

On Monday, speaking to FOX Business’ Liz Claman at the SALT conference, Cuban suggested he's not ruling out a future presidential run.

"Mark Cuban, president 20-whatever?" asked Claman.

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"Stay tuned," Cuban replied.

During the interview, Cuban — a self-proclaimed "hardcore capitalist" — also claimed Vermont Sen. Bernie Sanders and New York Rep. Alexandria Ocasio-Cortez aren't truly socialists.

“When they talk about socialism — whether it's Bernie Sanders — whether it's [Ocasio-Cortez] -- I think they recognize that it's a trigger word, and they use it just to get people all riled up as opposed to really being socialist,” he told Claman, recognizing it will continue to be a major talking point as the 2020 campaign heats up.

“As someone who's wealthy, as someone who is looking to benefit the company, every capitalist has got to do the same thing,” he continued. “We've got to say, look, if we at the top make a little bit less, and we help those at the bottom more, capitalism gets stronger. And it's not socialism, it's stronger and smarter and more, better capitalism.”

Fox Business' Julia Limitone contributed to this report.