Rain Man certainly didn't test really well. If you look at it carefully, you have a disease autism they didn't understand back then, they didn't know in the test audience whether it's okay to laugh or not laugh, because it's a film that's done in a way where, "Well, maybe I'm not supposed to laugh." At the end of the film, Dustin Hoffman gets on the train and doesn't even acknowledge his brother. Not even a glance, nothing. That's why the studio said, "Can't you just have him look at Tom Cruise at the end of the film?"