While promoting "Panic Room" before its release 15 years ago this week (on March 29, 2002), director David Fincher made a distinction between his "films" (arty works like "Fight Club") and his "movies" -- popcorn crowd-pleasers, which is what he considered "Panic Room."

Nonetheless, "Panic Room" feels like more than just a brutally efficient thrill machine. It's an intricate puzzle box and a psychological probe of our darkest impulses and fears, one that gave Jodie Foster one of her biggest hits and Kristen Stewart her first big break. It's all the more amazing in that, given its troubled production history, the movie even got made.

Let's celebrate it's decade-and-a-half anniversary with some trivia movie fans should know.
1. After the mind-bending complexity of "Fight Club," Fincher (above, right) wanted an easier project, and he thought he'd found one with David Koepp's "Panic Room" script, since almost all of the movie is set inside a single townhouse. But the shoot turned out to be anything but easy.

2. Fincher wasn't the first choice to direct. Initially, the producers had offered the gig to Ridley Scott, then to Forest Whitaker, who chose instead to take on the role of ambivalent burglar Burnham.
3. The first and biggest roadblock was the casting of the leading lady. Nicole Kidman was originally set to play Meg, the role Jodie Foster would take over. But Kidman had to bow out after two weeks when she aggravated a knee injury she'd suffered while making "Moulin Rouge."

4. Reportedly up for consideration to replace her were Sandra Bullock, Angelina Jolie, and Robin Wright. Ultimately, the filmmakers hired Foster, giving her only a week to prepare for the shoot.
5. Swapping Foster for Kidman changed the nature of the character. "It's like Hitchcock casting Grace Kelly," Fincher said of Kidman. "It's about glamour and physicality. With Jodie Foster, it's more about what happens in her eyes. It's more political. Jodie is someone who has spent 35 years making choices that define her as a woman and define women in film. Jodie Foster is nobody's f---ing pet, nobody's trophy wife."

6. Kidman can still be heard in the final film, however. When Foster's Meg calls her ex-husband (Patrick Bauchau), his new lady -- voiced by Kidman -- answers the phone. And you're welcome for that little Easter egg.
7. Similarly, daughter Sarah underwent major changes. Initially cast was Hayden Panettiere, but when she dropped out, the filmmakers replaced her with Stewart and made the character more tomboyish, to play up the contrast with Kidman's Meg. After Foster replaced Kidman, however, Sarah was rewritten to become more frail and vulnerable.

8. There were some changes behind-the-camera, as well. Fincher had hoped to use Darius Khondji, the cinematographer behind Fincher's "Seven," but the director and the lensman clashed over creative decisions. Fincher asserted control, Khondji left, and the less experienced Conrad W. Hall, son of famous DP Conrad Hall ("American Beauty"), replaced him.

9. Foster added one more speed bump to the production. Or should we say baby bump? Well into the shoot, she was visibly pregnant, which is why there are a number of shots of the actress wearing a sweater. Even so, part of the shoot had to be postponed until after Foster gave birth.
10. As Raoul, the frightening leader of the burglars, Fincher initially wanted to cast Maynard James Keenan, lead singer of Tool, with whom the director had worked on a music video. Eventually, he selected another musician, Dwight Yoakam (above, right), inspired by the country singer's villainous performance in "Sling Blade."

11. "Seven" screenwriter Andrew Kevin Walker has a cameo as a drowsy neighbor.
12. Most of the filming took place on a set built inside a soundstage near Manhattan Beach in California. Designed for maximum freedom of camera movement, the set cost $6 million to construct. But Fincher's fluid use of the camera, combined with the necessity of shooting many scenes twice (the second time for their appearance on the panic room's security monitors), ended up requiring nearly 2,100 camera shot setups, resulting in one of the lengthiest shoots of Fincher's career.

13. Of course, Fincher's own notorious perfectionism also lengthened the shoot. For one five-second scene, when Raoul attacks Meg and forces her to drop Sarah's medical kit, Fincher ordered more than 100 takes, so that the kit would land in frame and in focus, and so that it would be clear that she loses it and doesn't merely toss it away.
14. "Panic Room" cost a reported $48 million to make. It earned back $96 million in North America and another $100 million throughout the rest of the world.

15. Some critics saw a 9/11 metaphor in "Panic Room," with its plot about thugs invading and wreaking havoc on a supposedly secure Manhattan home. But that was just an accident of timing, since principal photography was finished before the Sept. 2001 attacks.
16. In the end, working in a confined space drove the filmmakers as crazy as it did the characters. When Entertainment Weekly asked him in 2004 what lessons he learned from making "Panic Room," Fincher said, "Don't shoot for 100 days in one place, that's what's to be learned from that. Figure out ways not to." He added, "They probably had that same kind of problem on 'The Shining' -- that's all in one house. [But] at least they get out, they get to run through a maze."