Many people know Mark Cuban only from his role as a "shark" investor on the popular TV show Shark Tank. But of course he is also a fabulously successful entrepreneur and investor who owns the Dallas Mavericks professional basketball team, Landmark Theatres, and Magnolia Pictures.

You might think you know Mark Cuban, but do you really? Here are nine things about this super-successful entrepreneur that might just surprise you.

1. In 2007, he was a contestant on the popular television show Dancing with the Stars. Although he didn't win, he did well--especially considering he began practicing with his dance partner only seven weeks after having hip-replacement surgery.

2. When Mark was just 12 years old, he made money to buy the expensive basketball shoes he wanted by selling trash bags.

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 Yahoo for $5.7 billion, personally netting about $2 billion in the process.

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. Said Cuban about the referee: "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 once went seven years straight without a vacation while building his own business). Says 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."