Feeding someone the belief that they are doing extremely poorly for an extended period of time until that one good occasion is a prime example of intermittent reinforcement.
A narcissist will talk about all of the positive aspects about your person, praising you for your beauty, intelligence, and whatever else they can think of in that moment in time to make you believe you are actually getting somewhere with them.
Always, without warning, they become a completely different person the next day. Insulting you on everything they complimented you on originally, saying how you’ve never cared for them or their needs, and any other kind of negative lie they can think of in order to make you feel worse about yourself than you did before.
One particular thing is very important to remember if you are ever caught up with a narcissist is that it is never your fault for feeling the way that you do.
You never did anything wrong to begin with, in fact, you were the person who made sure that this person was going to be happy one way or another and that’s exactly how they wanted you to be.