That's just downright stupid. Yet some people out there probably abide by it, or at least try to. It's just one of the many reasons I despise Christianity. To quoth Mouse of the Matrix, to deny our own impulses is to deny the very thing that makes us human. I'd find it very hard to survive if I constantly found myself worrying about how 'God' feels about me touching my own body.
Most men seem to believe that the more frequently they score, the more of a man they are.
Actually, I think anyone who isn't afraid to publically admit that they do indeed masturbate is more of a man than someone who supposedly scored with five different women last night all night long. Yeah, I'd say that's one of the outstanding reasons. However, it should be noted that, statistically, even many of those with active sex lives also masturbate on a regular or semi-regular basis. And yes, of course it's not true that masturbation is only for people with no social lives and no potential sex lives. Many people are of course foolish enough to tell you they believe that though, regardless of the fact that they do it themselves.