1. Director Richard Kelly mistakenly attributes the "cellar door" quote ("This famous linguist once said that of all the phrases in the English language, of all the endless combinations of words in all of history, that 'cellar door' is the most beautiful") to Edgar Allan Poe on the film's commentary track. The quote actually belongs to J.R.R. Tolkien (from his 1955 essay "English and Welsh"), and reads, "Most English-speaking people ... will admit that cellar door is 'beautiful', especially if dissociated from its sense (and from its spelling). More beautiful than, say, 'sky,' and far more beautiful 'than beautiful.'"
3. The short story that Donnie discusses in class, "The Destructors," was written by Graham Greene. Greene's birthday is Oct. 2 (1904). Oct. 2, 1988, is the day on which Frank tells Donnie that the world will end in 28 days.
4. Kelly sought permission from Smurfs creator Peyo for the scene in which Donnie and his friends discuss the Smurfs' sexuality. The estate allowed the scene because despite being graphic, it was accurate to the Smurfs mythology.
5. The film's Byzantine time travel plot isn't even entirely clear to its players. In his foreword to The Donnie Darko Book, Jake Gyllenhaal writes, "What is Donnie Darko about? I have no idea." So don't feel too bad if you're lost – Kelly hasn't exactly helped by releasing multiple edits of the film and a labyrinthine tie-in website.
7. The film grossed a sad, sad $727,883 during its initial release in the U.S., though it went on to become the definition of a cult hit, with DVD sales reportedly topping $10 million in the U.S. alone.
9. Part of the film's cult success can be traced to its run at NYC's Pioneer Theater, which played Donnie Darko as a midnight movie for an astonishing 28 months.
11. Donnie's very, uh, "adolescent" diatribe to his therapist about Christina Applegate was originally about Alyssa Milano – it had to be changed for legal reasons.
12. Initially, the film's poster had its title displayed in a vaguely Arabic-looking font. This was changed post-9/11, though the in-film credits still used the original typeface.
Frank tells Donnie that the world will end in 28 days, 6 hours, 42 minutes and 12 seconds. (Donnie draws this on his arm as "28:06:42:12.")
If you add those numbers up, you get 88. The film is set in 1988.
Since the film opens with Donnie receiving his directive from Frank, the film's narration ostensibly takes place over 28 days, but it was also shot over 28 days, and there are 28 scenes in the director's cut.
The flight number of Donnie's mother and sister's plane is 2806, which boards at gate 42 and leaves at midnight.
Freaked out yet? Go home and watch the movie in a dark room while contemplating these.