Where what you think is real, is completely different from what the majority of the population thinks is real. A common syndrome of politicians, (un)reality stars and musicians.
Symptoms:
Thinking that they are great at everything, despite all
evidence to the contrary.
Expecting everyone to praise them , often for doing nothing.
Getting angry when people disagree with their version of reality.
Not treatable, even by strong application of actual Facts(as opposed to
alternative facts) to the head of the person.
No, a large
blunt object does NOT count as Facts.
Not to be confused with some types of mental disorders , which are treatable.