The problem is if you play enough of parts in films that are sort of more financial products than anything or films in which the girl is a thankless, thoughtless, underwritten character along the way, you're no longer the person who had something fresh or vital to offer. I think it really does start to diminish some part of you, to put yourself through things you don't really want to be doing.
It seems that everyone has their own inexplicable fear to have nightmares about. We need nightmares to keep ourselves entertained, and fend off the contentment that we all fear and abhor so much.