Can You Be Too Nice?

I consider myself a nice person, but not overtly so. I don't dodge traffic and run two blocks to help an old lady cross the street, and I've never started a conversation with the person seated next to me on a plane. I'm civil, polite, and have reasonable manners, but I've never thought of myself as a "nice" person. Then a couple weeks ago I was at a party and ended up speaking with a guy I'd never met. We chatted our mutual friends for a few minutes and then he asked me where I was from. I told him, and then asked, "How'd you know I'm not from around here? My accent?" He told me that he couldn't pick out an accent, and then said, "You're just so much nicer than anyone from around here." It was odd because not only do I not consider myself super nice, but I also don't consider people from "around here" all that rude.