I saw that Roy was not inclined to be amused. I was not annoyed, for I am quite used to people not being amused at my jokes. I often think that the purest type of artist is the humorist who laughs alone at his own jokes.

Somerset Maugham, Cakes and Ale 

Our supreme insights must—and should!—sound like follies, in certain cases like crimes, when they come impermissibly to the ears of those who are not predisposed and predestined for them.

Nietzsche, Beyond Good and Evil 

Why so serious?

Heath Ledger, as the Joker, in The Dark Knight