I think the time that the Joker was genuinely telling the truth when Gamble tells him that he is crazy and the Joker replies. "I'm not.. I'm no--t!"
After all, he believes that the idea of society is a big joke, and the fact that people can get along together and have a sense of security can break down at any time.
After all, he believes that the idea of society is a big joke, and the fact that people can get along together and have a sense of security can break down at any time.