Unreasonable person

I start to understand how difficult to be a negotiator who can conduct a negotiation successfully.Those negotiator even negotiate with some people talk in reasonable way.My old landlord though he is chief and I am his soldier.I have to take every order from him.I am not going to go through the whole situation here,but the most ridiculous thing for me is he keep forgetting what he said and what he did before.He changed the reality and his memory to make himself believe one thing "He is right".Unbelievable !!!!