Remember? (1939)

“They lived their lives over again and laughed!”

Sky and Linda meet on vacation and become engaged. When Sky introduces Linda to his best friend, Jeff, Linda and Jeff fall in love and marry. But Jeff's work puts a strain on the marriage and a divorce is planned. Sky uses an experimental memory loss drug to make Linda and Jeff forget their rough times (and the fact that they were married) and they fall in love all over again.