We thought we did a pretty good job unearthing the secrets of "Donnie Darko" when the cult hit marked its tenth anniversary five years ago (it was released on October 26, 2001). But it seems that, with "Donnie Darko," there's always some new revelations to go along with the endless spinning of fan theories about the meaning of Jake Gyllenhaal's twisted time-loop journey.

So, in time for the film's 15th anniversary, here are 15 more things you didn't know about the eerie, funny, philosophical teen drama.

1. When "Darko" writer/director Richard Kelly graduated from UCLA film school in the late 1990s, instead of making movies, he was a lowly production assistant. He fetched coffee for the likes of Madonna, Jennifer Lopez, and Sean "Diddy" Combs. He realized he needed a calling card project and wrote the "Darko" screenplay in just six weeks.

2. Kelly said the germ of the story was the falling jet engine, which he said in a 2011 interview was inspired by a newspaper story he remembered reading as a child in his hometown of Richmond, Virginia, "about a big piece of ice that fell from the wing of a jet plane and smashed through this kid's roof and landed on his bed. He wasn't there at the time, but if he had been it would have killed him."

3. The script impressed many power players in Hollywood, but Kelly refused to sell it unless he could direct it as well. After sitting on the screenplay for a year, he found two bankable actors impressed enough with his vision to produce the film and let him direct it: Jason Schwartzman and Drew Barrymore. With them on board, Kelly was able to raise a modest budget and recruit the rest of his cast.

4. Shortly before the movie was to shoot, however, Schwartzman had to drop out over a scheduling conflict. Barrymore reassured Kelly that they'd be able to find a new Donnie. It wasn't long before the then-little-known Jake Gyllenhaal showed up in Barrymore's office to audition. "Right away, I knew he had the part," Kelly recalled in 2011. "Right away, he was Donnie."

5. As for the source of Frank, the film's creepy rabbit-guy, Kelly cited Richard Adams' novel "Watership Down," which was assigned reading in his eighth-grade English class, much like in the movie. "I came up with the idea of a kid in a Halloween costume," Kelly said in 2011, "and it just became a rabbit."

6. Kelly shot "Darko" in just 28 days -- the same time frame as in Frank's apocalyptic prophecy. Things went so fast that Kelly often forgot to eat. In a recent interview, Kelly claims this is typical film-set behavior for him and that he always loses between 10 and 15 pounds during a movie shoot.

7. It wasn't all stressful. In 2004, Kelly recalled that the scene where Kitty Farmer (Beth Grant) tells the principal exactly where Donnie told her to stick her lifeline exercise card made the director laugh so hard, that he had to be removed from his own set because he was ruining the takes.

8. As the sinister Jim Cunningham, Patrick Swayze (above) knew exactly how much he was trashing his own reputation as an '80s and '90s movie hero. Kelly said Cunningham's costumes came from Swayze's own stash of '80s clothing, and that the infomercial footage was shot on Swayze's own ranch.

9. The Halloween movie double-feature of "The Evil Dead" and "The Last Temptation of Christ" is one of "Darko's" slyest 1980s jokes. Kelly said he used "Last Temptation" because there was a scene, later cut, referencing the 1988 censorship scandal surrounding that controversial film. "Evil Dead" joined the bill because the rights-holders to the horror movie Kelly initially wanted, "C.H.U.D.," wouldn't process his request in time, while "Evil Dead" director Sam Raimi not only said yes right away but let Kelly use the film for free.

In a weird coincidence, Kelly claimed, on the night he filmed the theater marquee in Santa Monica, Raimi himself drove by with one of his children, who asked Daddy if his movie was really playing there in a double bill with "Last Temptation." BTW, Raimi's father-in-law was Bonanza" star whom Kitty Farmer confuses with author Graham Greene.

10. "Darko" premiered at the 2001 Sundance Film Festival, where it looked like it was going to join the folklore of Sundance discovery success stories. Even indie mogul Harvey Weinstein was walking around Park City with a "Darko" cap. But then the film screened, and its echoes of the then-recent Columbine High School massacre left buyers squeamish. Despite some critical buzz, Weinstein loudly passed on the film, and other distributors avoided it, too. Kelly went home without a deal.

11. "Darko" nearly went straight to cable before indie distributor Newmarket came to the rescue. It had enjoyed success with another 2001 Sundance orphan -- "Memento" -- so it had the resources to take a chance on another difficult film.

12. Newmarket faced an even bigger challenge marketing the movie after 9/11. Here was a grim, apocalyptic tale whose inciting incident is debris from a jetliner accident falling over Virginia. Its poster featured Arabic-style lettering, which Newmarket quickly changed to a more traditional Trajan font common on movie posters.

13. The film cost $4.5 million to make, but earned back just $515,000 upon its initial release. Even the 2004 Director's Cut release, after the movie had become a cult smash, earned just $728,000 in theaters.

14. Still, the movie made more than $10 million on home video, thanks to an ardent fan base that arguably started at Pioneer Two Boots, a pizzeria/theater that showed midnight movies in New York's East Village neighborhood. Kelly was walking past it one night when he saw his movie's poster in the window and learned that "Darko" had been selling out 2 a.m. screenings there for weeks.

15. Fans enjoy arguing over whether Donnie is a delusional schizophrenic or really has time-warping powers. Kelly has said both interpretations are valid, though he prefers the latter.

"I always thought of it as a superhero story," he said in 2011. "There's that line where Gretchen says, 'Donnie Darko? What the hell kind of name is that? It's like some sort of superhero or something...' And Donnie's like, 'How do you know I'm not?' That, to me, is the whole movie."