The line comes from the Joker in Tim Burton's Batman, released in 1989, where it became one of the film's most quoted moments. Jack Nicholson's calm delivery helped turn a strange, poetic question into a signature piece of dialogue for the character, linking him to moonlight, madness, and a dark sense of humour. Over time, clips of the line spread through fan edits, reaction videos, and soundboards, where its short length makes it easy to drop into a scene. It endures because it sounds both elegant and threatening at once.