I've been vegetarian since I was 13. I could say that it's all about animal rights, and I guess it sort of was at first, but truthfully, I really became a vegetarian to get some extra attention from my mother. Becoming vegetarian was my whole "teenage rebellion" phase (yeah, I was a bad girl back then

). I was studying debates in English class and I got the subject of being
for animal rights. So learning about slaughter houses and seeing pictures of what the effects of cosmetic testing would be if it were done on humans, etc. etc. and I was disgusted by it.
When I first announced my decision, I was told that it was okay, as long as still ate fish, which was fine with me. So here I am, twelve years older and still vegetarian... I did have a short period where I began eating chicken and turkey again because I was hospitalized for several months in a small hospital and I didn't really want to eat canned salmon and canned chickpeas on green salad a couple of times a day. When I first went back to it, it lifted my stomach and I never got to the point of liking it.
All in all, being vegetarian has just become a lifestyle for me and I don't think I'll ever be able to give that up, which is fine with me - I actually know more meat-eaters who have had problems with anemia than vegetarians.