Who said "The joke's on everyone who thinks they understand me."?

This quote is attributed to The Joker.

The joke's on everyone who thinks they understand me. - The Joker

"The joke's on everyone who thinks they understand me."

The Joker Humor

"All you care about is money. This town deserves a better class of criminal."

"I'm not a monster. I'm just ahead of the curve."

"Madness is like gravity. All it takes is a little push."

"Everything burns."

"Never underestimate the power of a good laugh."

"Laughter is the best medicine."

"A good laugh is the best medicine."

"Laughter is contagious and wonderful."