Watch Donald's Dilemma (1947) Official Trailer

Donald and Daisy are walking when he is hit by a flowerpot. He's convinced he's a famous singer, and he croons divinely, but does not recognize Daisy. He in fact does become famous. Daisy is devastated by her inability to get over him and sees a psychiatrist. He tells her she has to choose between the world having Donald, or her getting him back. She picks herself, and drops another flowerpot, which restores him.