I think it's that I have an incredibly odd and different sense of humor then most, though it's gotten much better as I've dealt with other personal issues. I'm more a slap stick comedy kind of guy, loving the hell out of the Three Stooges and other such slap stick comedies, so the majority of regular jokes seem to fly over my head. And I also have a hard time telling what's a joke when it's just written down so that doesn't help either.