I have often said (yes, really) that one of my greatest fears is that I have some obnoxious character trait/flaw that I'm personally unaware of and that people are too polite to tell me. Well, now's your chance to speak up!
My Nohari Window
Use a pseudonym if you're worried I'll get huffy on you. Though really, the worst that could happen is that I drop you a line to inquire anxiously what I did/said that gave you that impression and how I might be able to avoid making the same mistake in future.* I have my share of flaws, but I am seldom violent or hostile.
*unfolds lawn chair, munches on a molasses cookie*
* Assuming it’s something I feel I ought to correct, that is. It might not be, because I’m just that arrogant (which is, sadly, not on the list. Though smug is, which I’m sure at least some of you will find useful).