.. are principally a subtype of delusional disorder but could possibly feature as a symptom of schizophrenia and manic episodes of bipolar disorder, from maybe smoking too much dope where the victim tends to abide in what used to be commonly called an " Ivory Tower ".
The delusion (common in paranoia) that you are much greater and more powerful and influential than you really are .. but knowledge is power, and the wisest man knows nothing at all.

