Mark Cuban, the deadly investor on Shark Tank, the owner of the Dallas Mavericks, and the billionaire we all know, like everyone else, started somewhere.

Here are some of Cuban’s most significant failures:

  • Couldn’t learn carpentry as a fall-back trade.
  • The bar he started in college was shut down when a 16-year old won a wet T-shirt contest.
  • After graduating from Indiana University, he quit his job at Mellon Bank because he didn’t like the CEO.
  • His Powdered milk venture failed after his parents were his only customers.
  • After moving to Dallas, Cuban got fired from his sales job at a software company after closing a deal without the CEO’s approval.

Getting fired led him to start his own computer systems company, MicroSolutions. Still, 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. Cuban counted the months he was in business, hoping to outlast his previous endeavors. Even with his nascent success, there were setbacks. For example, his secretary stole $82,000 from Microsolutions.

Cuban learned, “Even when you have every ‘i’ dotted and every ‘t’ crossed, something is going to go wrong. And when it does, you just have to fight through it and grind through it. Remember what it is that makes you special, and what it is that makes you confident to do what you do, and do more of it.”

Cuban sold MicroSolutions to CompuServe for $6 million in 1990, making him a millionaire at 32. He co-founded a company called Audionet, which became Broadcast.com. Yahoo acquired it for $5.7 billion, and Cuban became a billionaire at 40. Today, Cuban is worth $4.1 billion, according to Forbes.

As Cuban wrote in his book, “It doesn’t matter how many times you almost get it right. No one is going to know or care about your failures, and neither should you.” And we certainly remember and know Mark Cuban for his successes, not his failures.