I think I tend to have the same sort of mindset around work.

To some degree, you can only really have a horrible boss if you let them get to you. If you can be ok with the worst case scenario, then you don't have to be strongly emotionally impacted by whatever your boss says or does.

That said, I've never had a terrible boss. I've had incompetent bosses and bosses who didn't like me, but none who were just openly abusive or hostile.