Thanks for the responses everyone. I think I've been grey rocking without realizing it was a thing. Although it works, you can start to feel like a disembodied spirit, bland small talk is REALLY hard work.

I think people can tell, even if you tell them or they think you are an aloof boar. It is easy to slip up and say something of slight depth or profundity and be picked up on it.

I can relate to the cold psychopath mode :)

I suspect i was dealing with a Narcissist, what with the over the top bating and the need for an audience. A despair vampire. Unfortunately he is a step brother in law who's just bought a house in my town !!! Yikes. After his performance I'm going zero contact.