Rain Man is a 1988 American drama film directed by Barry Levinson and written by Barry Morrow and Ronald Bass. It tells the story of an abrasive and selfish young wheeler-dealer, Charlie Babbitt (Tom Cruise), who discovers that his estranged father has died and bequeathed all of his multimillion-dollar estate to his other son, Raymond (Dustin Hoffman), an autistic savant, of whose existence Charlie was unaware. Charlie is left only his father's car and his collection of rose bushes. Wikipedia
(Raymond doesn't want to go outside when it rains)
Charlie: Hey, Ray, you take a shower right?
Charlie: Well the rain is a lot like the shower, you get a little wet. What do you say, Ray? What do you say?
Raymond: Of course the shower is in the bathroom.
Charlie: That's the end of that conversation.