I think people should have the legal right to hurt themselves without fearing that they're going to get locked up for doing so. But on a personal level if someone I loved was hurting himself or herself in front of me I would of course try to restrain them.
A lot of what I've been learning in the last two years is due to therapy - about my sexuality why things go wrong why relationships haven't worked. It isn't anything to do with anybody else it's to do with me.