I actually don't think I'm that picky an eater overall, but I have that reputation because I dislike certain specific popular foods, like pickles, crappy pizza, and, hey, most ketchup and mustard. Especially as a little kid I had the reputation among friends' parents and relatives as ridiculously picky because I disliked a bunch of standard "crap we give kids who come over" tropes, despite that I also liked a lot of things kids aren't supposed to like (vegetables, etc.)