"What is your tennis ball?
This question, derived from a terrific commencement speech given at MIT last year by Dropbox founder Drew Houston, is a good place to start because it cuts to the chase. As Houston explained, “The most successful people are obsessed with solving an important problem, something that matters to them. They remind me of a dog chasing a tennis ball.” To increase your chances of happiness and success, Houston said, you must “find your tennis ball--the thing that pulls you.”
Via Kenneth Mikkelsen