One of the things that has kept me sane over the years is to always be ready to walk away at an instant's notice. I think of this as being something like a cognitive mobility bag.

Readiness is an attitude. It helps to have the right tools for preparedness—which is why some people keep an actual mobility bag by the door—but a lot of it is always thinking through your options, always having alternative plans, and never being backed into a corner. Always have an out.

This isn't something that can be instantaneously wished into existence. In order to be prepared to strike out alone—to leave a job, to leave a residence, to leave friends or family—you have to construct your life around the idea that things can change suddenly, and, if things change in a way that are prejudicial to your interests, you might be better off leaving the situation. Then you leave and don't look back. Ghost.

Most people aren't ready to walk away. They stay in suboptimal situations for many reasons, like fear of the unknown, fear of being alone, fear of starting over, fear of abandoning an investment, and so on. Others count on this to manipulate those who can't walk away from a bad situation or won't walk away from a bad situation.