I was once on an airplane, seated next to the manager of the entire western region of some giant conglomerate (like ATT or something). I told her I had absolutely no ambition whatsoever, and she laughed for twenty minutes. She thought that was the funniest thing she'd ever heard.
I end up out of my comfort zone, A LOT. I deal. But I don't especially seek it. I've heard the personal growth folks say 'do one thing you're scared of every day.' I faced almost all my fears, I think I get to sit on the porch with an iced tea now, thanks.
I appreciate your naming it.