What I mean by passion is not just that you have something you care about. What I mean is that you care about that same ultimate goal in an abiding, loyal, steady way. You are not capricious. Each day, you wake up thinking of the questions you fell asleep thinking about. You are, in a sense, pointing in the same direction, ever eager to take even the smallest step forward than to take a step to the side, toward some other destination. At the extreme, one might call your focus obsessive. Most of your actions derive their significance from their allegiance to your ultimate concern, your life philosophy.
From Grit by Angela Duckworth