I'm a veggie, started out by slowly cutting out meat from my diet, and gelatine, as I didn't like the taste or the idea of eating animals. I kept eating fish for a while, partly to maintain the whole gradual process thing while I got used to finding non-meat sources of protein/iron etc., and also as a sort of compromise with my parents, who aren't very good with the veggie thing and were hugely concerned about what I was eating. Now I don't eat fish either, but get horribly paranoid about things containing gelatine or animal fat or anything. I also used to be anaemic, and had to take iron tablets.
Falafel is great. Ditto hummus.