Michelle Pfeiffer's character is forty years old in this movie, while the actress was actually forty-seven at the time of shooting. Her co-star Paul Rudd was thirty-six in real life, although his character was twenty-nine and played the role of a teenager in the TV show inside the movie. But perhaps most unbelievable was Stacey Dash, who plays a teenager in the show within the movie, but was forty years old at the time of production.
Norm MacDonald was originally cast as Rosie's ex-husband. According to MacDonald, he grew a bushy mustache for the role. When Amy Heckerling told him to shave it off, he quit the project.
When Michelle Pfeiffer is auditioning "nerd" characters for her TV show, her assistant announces that the first actor candidate's name is 'Neil Israel' -- who worked as a director on Amy Heckerling's "Clueless" (1996) TV series and a writer on her feature Look Who's Talking Too (1990).