Since we're in an introspective mood, this raises the interesting question of how much of a role what you do plays in defining how you think of yourself and how others do. To my neighbors, nearly all of whom I don't know very well, I'm 99% sure that I'm "that guy who rides a bike." To my friends at work, most of whom are also engineers, they presumably don't think of me as just "an engineer." Not sure who they think I am.