They’re all narcissistic and a narcissist doesn’t even interact with reality much at all. They can’t handle reality, so they interact with their warped perception of reality and delusional projections instead. They surround themselves with people who reinforce those delusions. Once you criticize them or introduce some acknowledgement of reality (like the idea that they have flaws or aren’t the best person on earth) they make you their enemy.

So they genuinely believe that if they proclaim something to be true, then it is.