When I was little, like 4 or 5, I remember answering someone with a longer-than-acceptable answer and apparently whomever I was with (can't remember if it was my mom or dad) didn't approve of my answer.  I remember being told that all you had to say was "I'm fine" so...that's what I usually do. If I have a bad day/week/etc, like when my mom was in the hospital and I got to school and someone asked me, I said "I'm all right" because after all, I am all right, even if I was stressed out. I never asked back until late in high school when I finally realized you were supposed to ask back.

What I hate even moere is when people (one of the vets I work with, in particular) instead ask "What's up?" or "What's going on?" or "What do you know" because I'm not prepared for those and I usually just say "Nothing", then once when I did that the guy asked "You're a college student and you know nothing?"   *sigh*