Apart from a certain solitary activity, all other sensations caused by our own action are filtered out or muted by the brain so that we can focus on external stimuli. There is a famous experiment which demonstrates an unintended consequence of this otherwise useful system.
You and I stand before each other with hands extended. We are going to take turns pressing a finger onto the other’s palm. Each of us has been secretly instructed to each time try and match the force the other has applied in the previous turn.
But what actually happens is that we press down on each other progressively harder and harder at every turn. And at the end of the experiment each of us reports that we were following instructions and it was the other that was escalating the pressure. Indeed, the subjects in these experiments were asked to guess the instructions given to their counterpart and they guessed that the others were instructed to double the pressure.
What’s happening is that the brain magnifies the sensastion caused by the other’s pressing and mutes the sensation caused by our own. Thus, each of us underestimates the pressure when it is caused by our own action. (In a control experiment the force was mediated by a mechanical device –and not the finger directly– and there was no escalation.) So each subject believes he is following the instructions but in fact each is contributing equally to the escalating pressure.
You are invited to extrapolate this idea to all kinds of social interaction where you are being perfectly polite, reasonable, and accomodating, but he is being insensitive, abrasive, and stubborn.