Ask YC: Does it hurt to apply more than once?

This may have been covered before, so apologies if it's a dupe.

Does it hurt to apply more than once? That is, once you get dinged, is there some sort of "uh-oh, it's that guy again" that happens the next time around? Or do each time you get treated like it's your first time up?

I'd like experience applying, if nothing else. But I don't have a co-founder and don't want to hurt my future chances by using up any of my "free karma" on a long-shot application.