Originally Posted by ALP
I've always said I thought Ledger's Joker was a man who probably did a stint locked in a psych ward in another state then he broke out and took the first train to Gotham. So insane and deprived of reality that he probably doesn't even know what his real name is.
But why the face of a clown?
I'd guess he was drawn to that persona because of a belief that modern society and its standards and values are a sick joke. Of course, he has an unyielding desire to be noticed, so the theatrical persona makes some sense, especially if he was inspired by the appearance of the Batman.