Henry Ross (Adam Sandler) is a typical playboy. What he is best at is to make beautiful women fall in love with him in different identities, and then quickly get out of the relationship afterwards. As a veterinarian at the Hawaii Oceanarium, Henry has endless romantic feelings to infect the beautiful women who come here to relax. This time he fell in love with Lucy (Drew Barrymore) who was dining alone in the restaurant. They talked about everything together, built a small house with bagels, and laughed constantly. Henry was reluctant to leave the girl and made an appointment to dine together again tomorrow morning. However, the next morning, when Henry greeted Lucy enthusiastically, Lucy was as cold as a stranger. It turned out that the girl suffered from a strange short-term memory loss due to a car accident, and her memory always stayed on the day before the car accident. The love saint Henry encountered his own problems. He fell in love, but fell in love with a girl who kept losing her memory of love...