For a large-ish portion of my life to date -- thankfully decreasing as a percent every day -- almost all compliments carried with them implicit negative comparisons. It couldn't just be, "What a great dress on you!" It was almost always, "What a great dress on you! I could never wear something like that, it would make me look like [a cow/a wall/some other negative thing]." Some of the girls who learned this pattern were being perfectly sincere, and that was bad, because who wants to make their friends or even their cordial acquaintances feel worse just by showing up? And some of them were fishing for compliments, which was bad, too, because it made it feel like they wouldn't have brought the subject up to begin with otherwise. And you certainly can't smile and say, "Thanks!" when someone had just said, "You look great and I look terrible!"; not unless you dislike them and want them to think they look terrible. You can't feel warm and fuzzy about it. You have to go into caretaker mode -- um, maybe that part is just me, actually -- and try to make it all better, and later when you think of it, that's what you think, not "so-and-so liked my dress."
(Boys were much less of an issue. I think most teenage boys had the feeling that complimenting a girl would be equivalent to publicly offering to raise children with her or something like that: a large commitment of interest at the very least. And many girls seemed to reinforce that belief, so. Men of my acquaintance have a firm grasp on the difference between, "Nice dress" and "please reproduce with me," and for this I am deeply grateful.)
So now when matociquala pops up today saying I would Stop Traffic (caps hers) if I bought a corset at World Fantasy as I have threatened to do, it is a delightful relief that her own traffic stopping abilities are not in question here simply because she has raised the subject of mine. (I mean, the Bear, the jade green corset, the boobs, and did I mention that it was green? And did I also mention the boobs? So: not in question, really.) It's just unadulterated nice. It's very cool but also fairly new. I'm still practicing with this bit.
This is almost certainly not the only problem I have with taking compliments, but it's on the list.
I also tend to want to verify that people know that they're totally making up who is pretty and who is not. It's not necessarily a bad thing to be making it up, I just want to know that they know they're doing it. Social construct and all that. Standards and tastes vary etc. Everybody got it? Okay then.