Sometimes it just hits you in the right way. Jimmy Fallon and Bradley Cooper were talking about the actor's role in the play The Elephant Man, when they got off on a bit of a tangent about their funny hats.
A perfectly-timed segue by Cooper, "Anyway, I went to London, I went to see his bones and it was amazing..." and they were off to the races. Fallon and Cooper simply could not stop laughing after that. What follows is several minutes of them trying to get back to the interview without success.