He Kept A Joker Journal
Ledger had a diary full of sad news stories; pictures of Alex DeLarge (A Clockwork Orange); a hyena; a smiling clown (which hell no because clowns are freaky and in no way for a child’s entertainment. Pennywise? Enough said). Ledger apparently kept this journal with him at all times in case he needed a reminder of the sadistic dark character he was playing. So think of it as a “vision” journal, but for the criminally insane. While most people may have photos of exotic places or dream jobs, this guy had a picture of a smiling clown.
In another twist, although Ledger would always be dressed in character (even when not shooting his scenes), he didn’t always stay in character. Much to the appreciation of his cast mates, I’m sure. Unlike Jared Leto and his creepy presents, Ledger didn’t have to go to those extremes. That is what the journal was for, right?