I’ve dealt with quite a few people on the disordered thought spectrum. Most of them aren’t as witty as Kurt, but some of them do use a similar way of thinking, flitting from toppic to topic, circumferential and tangential thoughts, etc.
And there is one area in Breakfast of Champions where Kurt says that the word schizophrenia always reminded him of sneezing in a blizzard of snow flakes and that “Word of honour, I am better now”. It sort of implies that he had, at least, brief psychotic disorder, manic-deperession or (most likely) schizoaffective disorder. Is this actually documented anywhere? Is this what makes Vonnegut brilliant?