James Park is only 39 years old, but he is already considered one of America’s most successful entrepreneurs. Park is co-founder and CEO of Fitbit, the company behind the popular fitness trackers.
There’s a lot of money in tracking people’s steps and other biometrics. Fitbit has sold millions of its trackers and last year accumulated nearly $2 billion in revenue. (The company went public on the New York Stock Exchange in June 2015.) It was a banner year for Park—one that helped land him on Fortune’s 40 Under 40, our annual ranking of the most influential young people in business.
The CEO has a remarkable story. He dropped out of Harvard University when he was 21 years old to start his own company even though he didn’t know much about business.
Park recently shared with Fortune’s Susie Gharib what he learned about running a successful company, mistakes he made along the way, and the best advice he got on what it takes to be a leader.