In an early scene, a dentist and a woman in the dentist's chair are seen talking with each other. The woman playing the dentist is Jackie Sandler, Adam's wife, and the woman in the chair is played by Linda Segal, Director Peter Segal's wife, who is a dentist in real-life.
Of the three movies Adam Sandler and Drew Barrymore made together, this is the only one that was number one at the box office and made over $100 million.
The movie is dedicated to Adam Sandler's father Stan Sandler, who died while the movie was in production.
The diner where Lucy has her breakfast every morning was originally a house that was remodelled for the movie. It is located on a macadamia nut farm on the eastern side of Oahu. The same house was used in Tears of the Sun (2003) and scenes from Jurassic Park (1993) were filmed in the open fields nearby.
The neurological condition from which Lucy suffers, Goldfield Syndrome, is entirely fictional. True anterograde amnesia affects either short-term memory, which can last minutes or seconds, or intermediate-term memory, which can last days or weeks. Falling asleep has nothing to do with the condition, and sleep actually intensifies many chemical effects which help memory.