I hate costumes. I hate dressing up in general. I feel woefully incompetent at anything where physical appearance plays a big role. It's not that I think I'm inherently bad to look at or anything like that. It's that I think there is a certain skill to presenting yourself well from a pure visual appearance standpoint that I don't think I possess.
So I've been staying away from almost any event or social gathering in which clothing is mentioned.
Previously, I've gone for minimalist conceptual costumes as a way to avoid the whole question all together. "I'm a college student." (in actuality a bit bitter than I wasn't really a college student by the official definition and therefore didn't qualify for any financial aid) or "I'm an amorphous blob named Xylex who's eaten me and taken my form." or "Starman." (that was a bunch of big steel marbles I was holding in my hand, sadly they didn't glow).
Now, somehow, that isn't working for me. I'm not sure why, but I don't really want to try the conceptual costume route, and I don't really want to dress up either. I have nothing to dress up in and no skill at doing it. In fact, it's often a huge effort for me to get out to various events in the first place, and I kind of resent being presented with an additional requirement to dress a certain way if I'm going to be there.