Titles (of people, not books)

I was thinking about titles today, because Molly's principal seems to be referred to by the parents as either Dr. Firstname or Dr. Lastname. She holds a PhD, I assume, and it's very odd to me to hear people call her doctor, because I think of a doctor as something medical. Let me just add, for anyone who doesn't know this, that both my parents hold PhDs. I think that actually makes the whole calling-a-PhD-holder-a-doctor thing that much weirder for me: I grew up surrounded by people with PhDs, but I only ever saw them socially, and of course they didn't demand that the children of their colleagues address them as "Professor Smith." This being Madison, they weren't even "Mr. Smith," they were just "Bob."

Do you have a professional title? (Or a military rank? Or, if there happen to be members of foreign nobility reading this, an interesting social sort of title?) Under what circumstances do you use it, or expect others to use it? Do you ever whip it out as an unsubtle "well fuck YOU, buddy, it just so happens that I AM a rocket scientist" move? Does it make you twitch when people address you by your professional title in a social situation? Does it make you twitch when people just call you by your first name in a professional situation?

My only degree is a B.A., so the Impressive Professional Titles game is obviously not one I get to play.