You've run into a person, and this is very prevalent, who confuses something they do with who they are. It is a sign of a not wholly developed psyche. They internalize something they are better at than most people and integrate it into their personality, and it becomes part of their ego.

Either learn to let them stay confused in their ignorance, or say fuck it and burn a lot of bridges as you go through life. I've tried both approaches, and find the live-and-let-live approach better for me.

Heavy use of psychedelics decreases this phenomenon.