User blog comment:Kltt05/What Nolan Film did you like best?/@comment-5173400-20120808162059/@comment-3202167-20120809060701

That is because he has mental problems.

And again, not sure what is with the orange hair, never saw Joker with orange hair *Minus the scene in the hospital*

Hell, maybe he actually hates Batman, so he went there, shot everything and said that he is Joker.