Why do men like big boobs and butts?

So I know this has been asked like a hundred times before, but I feel like being a little stinker (>:D) and asking SERIOUSLY WHY DO MEN LIKE THEM?! I mean, they are lumps of extra fat. If I were a man, I think that I wouldn't care less how big a woman's boobs or butt are. And why do you men think they are so attractive to look at? Yea I know I know because you don't have them but whatever. I don't think that plays a big part in it. And what about girls who are flat chested? Is it really fair to them that most men like big boobs? It's not their fault they aren't big chested because I'm sure they wish they could have more fat up there. (I'll admit I'm flat chested and I usually don't care about being so because it fits well with my skinny body. But from time to time, I still wish I had boobs. And I mean I am flat chested, I'm not just some girl who has small boobs and is over exaggerating. I have nothing to work with, but then again I really don't care.) And there isn't anything they can do about it, because men complain about fake boobs too! I mean really this whole subject interests me. And also, I know you guys also think about us, "Why are women infatuated with tan guys who are tall and buff?" This isn't true. I know many girls, definitely including myself, who would rather have a skinny, nerdy but cute guy over the hottest jock in school. In face, nowadays I fall for ONLY skinny guys who don't get much attention. And for the record, I really don't care about penises either. (Well, I mean you gotta have one at least XD) I just want a guy who is funny and cute. :P So, there is my question along with some pondering on my part. Feedback?? :)