Psychopathy
The exceptional thing about writing characters who are psychopaths is that they can become a fountains of one-liners. A literary psychopath—the real thing probably not so much—are like a gift from god for their ability to inform any subject imaginable with menace and the sinister quality of psychopathy:
“Memories can be vile, repulsive little brutes. Like children.”
Madness
What is madness? Well, the Joker is pretty close, that’s for sure. But perhaps madness is not really as far out as it seems. At least the Joker thinks so. Of course, he’s mad, so take that for what it’s worth:
“So when you find yourself locked onto an unpleasant train of thought, heading for the places in your past where the screaming is unbearable, remember there's always madness. Madness is the emergency exit.”
Insults
Insults are also fun when psychopathy is involved. You take that emergency exist and madness opens up a wealth of potential for insulting people. Because, you know, it doesn’t really have to make complete sense when you’re a little mad. Even if your madness happens to be of the Batman type rather than the Joker sensibility:
“Now, you whimpering little smear of slime, I’m going to politely ask you one more time.”
Reinvention
The Dark Knight film was far from the first to hand an uncertain past to the Joker. He’s never really been easily pinned down on the what, when and why that led to the who and how. That fuzzy background goes way back:
“If I have to have a past, then I prefer it to be multiple choice.”
Not so Much Funny “Ha-Ha” but Funny
Psychopathy also induces black humor. Hey, you don’t grow up to be a super-villain who calls himself Joker without having a sense of humor. Like the time Barbara Gordon goes really, really limp. Resulting from, you know, a little of the ultraviolence:
“Please don't worry. It's a psychological complaint, common amongst ex-librarians. You see, she thinks she's a coffee table edition.”
