*Question your tendency to pity too easily.*
Respect should be reserved for the kind and the morally courageous. Pity is another socially valuable response, and should be reserved for innocent people who are in genuine pain or who have fallen on misfortune. If, instead, you find yourself often pitying someone who consistently hurts you or other people, and who actively campaigns for your sympathy, the chances are close to one hundred percent that you are dealing with a sociopath.
Related to this-- I recommend that you severely challenge your need to be polite in absolutely all situations. For normal adults in our culture, being what we think of as "civilized" is like a reflex, and often we find ourselves being automatically decorous even when someone has enraged us, repeatedly lied to us, or figuratively stabbed us in the back. Sociopaths take huge advantage of this automatic courtesy in exploitive situations.
Thirteen Rules for Dealing with Sociopaths in Everyday Life Martha Stout - Interview
Author: The Sociopath Next Door