I try to imagine every possible way that conversation could continue and every single one of them was more depressing than getting myself to shut up then and now, which was also bad but like, least bad in context
I usually avoid doing it with politics since it's pointless to argue about people's religious beliefs. I'm still easily drawn into long arguments with idiots though. The main reason is it bothers me that they're misleading other people. It doesn't happen in a private message.
The worst is trying to distinguish between stupidity and trolling, but it ends up not mattering since I'll want to stamp out the misinformation anyway. On the positive side, if I think it's trolling, sometimes I can just ban them or threaten to do it.
Also not very fun is trying to figure out which of my followers are Nazis and what to do about that since I don't particularly want to piss them off. They recently came and posted some nasty images in a Matrix channel with aliases http://matrix.org admins took from them.