As the nerdy but nice kid in high school, Ted (Ben Stiller) was in heaven when the most popular girl in class - Mary (Cameron Diaz), chose to go to the prom with him. As it happens, Ted had quite a traumatizing and painful accident so the date was cancelled - and 13 years later he still thinks about the 'one that got away' - so he hires a private investigator (Matt Dillon) to track her down and get some closure.

As it turns out, there is something about Mary because every guy alive has fallen for her charms.  Ted is ratted out by an anonymous letter sent by his best friend - who was Mary's boyfriend in college and part-time stalker which is the reason she moved to Miami and changed her surname.  Ted confronts the PI and Norm/Tucker (Lee Evans - a pizza delivery guy pretending to be some type of doctor or architect), and together they go to Mary's apartment and rescue her from the crazy stalker.
  Ted is the only one who cares deeply for her well-being, and he has tracked down "Brett", who just happens to be super-rich US football star Brett Favre.  Norm admits that he made up the stuff Brett said about Warren, and Ted walks away crying his heart-out leaving them to be happy-ever-after.
  Almost at his car, Mary chases after him -- only to give him his keys.  But, of course, she has chosen him as the best man for her and they kiss.  Meanwhile, the old guy sleeping with Magda takes out a sniper rifle as he was only using old Magda to get close to Mary - but the bullet misses the target and takes out the random musician instead.