What did you like to do most when you were a teenager? According to Bill Gates, the answer to this question will tell you what career you should pursue. “The thing you do obsessively between age 13 and 18, that’s the thing you have the most chance of being world-class at,” he told Charlie Rose in an 2016 interview. So answering that simple, if offbeat, question can give you some clues about where to focus your energies.