"The trouble with the world is that everybody is three drinks behind."
- Humphrey Bogart

"What contemptible scoundrel stole the cork out of my breakfast?" - W.C. Fields
Off the set, Humphrey Bogart and Ingrid Bergman hardly spoke during the filming of Casablanca. This is perhaps due to two reasons: (1) Bergman was taller than Bogart and perhaps he had an inferiority complex, or (2) Bogart's wife Mayo Methot continually accused him of having an affair with Bergman. Methot often confronted him in his dressing room before a shot, causing Bogart to come onto the set in a rage.
While filming the love scenes, Bogie was so stiff and cold with his performance (which is how he always performs, IMO) that director Billy Wilder was heard to have said, "One of the most beautiful women in the world and he looks like he's forcing himself to kiss her."