You might think you know Mark Cuban from Shark Tank, but how much do you really know? Here are nine things about this tech maverick that might surprise you.

1. He competed on the television show Dancing with the Stars in 2007 seven weeks after undergoing hip-replacement surgery. Unfortunately for Mark, he didn’t end up winning.

2. When Mark was just 12 years old he started a business that sold trash bags. He used the money he made to buy a pair of shoes that he had been eyeing.

3. Cuban made his way into the Guinness Book of Records in 1999 by making what was then the largest single e-commerce transaction. And what did he buy? A Gulfstream V private jet–for $40 million.

4. Mark could afford to buy that private jet because in 1999 he sold his company,, to Yahoo for $5.7 billion. He personally netted about $2 billion from the sale.

5. The NBA has fined Mark more than $2 million, for a variety of different infractions. His largest fine–$500,000–was the result of a remark he made about an NBA referee. Cuban said: “Ed Rush might have been a great ref, but I wouldn’t hire him to manage a Dairy Queen.”

6. After making the Dairy Queen comment about Ed Rush and earning that $500,000 fine, Cuban accepted the invitation of a local Dairy Queen to work behind the counter for a day.

7. Mark met his wife Tiffany Stewart at a gym, and they dated for five years before marrying in 2002. Tiffany is 14 years younger than Mark.

8. Mark credits Ayn Rand’s novel The Fountainhead with giving him the courage to take risks and to be responsible for his successes and failures.

9. According to Mark, success requires hard work and focus. He claims that he  went seven years without a vacation while building According to Cuban, “There are no shortcuts. You have to work hard and try to put yourself in a position where, if luck strikes, you can see the opportunity and take advantage of it.”