Buster Keaton, of course, was known for his frozen face. The fact that he didn’t smile when something clearly hilarious to us befell him was his trademark and the secret to his success. He stood out amongst his comedic contemporaries because he didn’t overtly look as if he were in on the joke. But we do know that off-screen, Buster was often one to laugh and even, according to those who worked with him, prone to ruining his own takes.