Did Humphrey Bogart really say "Play it again Sam"? And what movie was it in?
In fact, nobody does.
There are two exchanges that come close. The first takes place between Ilsa Lund Laszlo (Ingrid Bergman) and Sam (Dooley Wilson).
Ilsa Lund: Play it once, Sam. For old times' sake.
Sam: [lying] I don't know what you mean, Miss Elsa.
Ilsa Lund: Play it, Sam. Play "As Time Goes By."
Sam: [lying] Oh, I can't remember it, Miss Elsa. I'm a little rusty on it.
The second takes place between Rick and Sam.
Rick: You played it for her, you can play it for me!
Sam: [lying] Well, I don't think I can remember...
Rick: If she can stand it, I can! Play it!
It's been reported that "play it again, Sam" originated in the 1946 Marx Brothers film A Night in Casablanca, but we can't confirm that, not having seen the film ourselves.
For more movie history and information check out the Movie channel at infoplease.com.
—The Fact Monster