There's about 3 to five different origin stories, by my count, and some of them have variations. The most prevelant one is that the Joker used to be...
Likes writing The Corleon Tales, and drawing and surfing the net.
Occupation:
none of your beezwax!
Signature
It's Winter though it's Summer[In our hearts]
We'll be close together even when were far apart
Your words are being drowned out by the fireworks
Can't hear the important details, but I seem to know what they are
Though you can't see me, we'll be close
Just us two.
cause....
I'm thinking of you