Blink and You'll Miss It
David Fincher says he made Fight Club (sure you did, Dave) but it feels like Tyler Durden made it. The film is a single story, and Edward Norton or Brad Pitt (the two sides of Tyler) appear in almost every single frame—along with the ubiquitous Starbucks cup, of course.
This is ultimately his journey. Tyler's the narrator. Unfortunately, he's an extremely unreliable one. He doesn't even realize that he is Tyler Durden until the last twenty minutes of the movie. His chronic insomnia makes nothing seem as it is really is. Early on, he tells us, "With insomnia nothing's real. […] Everything's a copy of a copy of a copy." So it makes sense that his view of the world is less like reality and more like, well, a movie.
In fact, our narrator sometimes explicitly refers to his life as though it's a movie. After realizing that he and Tyler are the same person, he passes out (insomnia will do that) and his voice over says, "It's called a changeover. The movie goes on, and nobody in the audience has any idea."
Except we do have an idea by this point because he just told us. This is one of many cinematic techniques that are normally hidden from audiences, but here are exposed to us, like the psychological motivation for our main character.
Tyler also works as a projectionist, teaching us some (now outdated) tricks of the trade, like how a cigarette burn—which is a small spot in the upper-right corner of a movie reel— signals the projectionist to change reels. This is the changeover he later mentions.
Watching this film on DVD changes the feel of the whole thing. In theaters there are many actual cigarette burns, which would make the viewer wonder if they were planted there intentionally by David Fincher (or Tyler himself), or if they're part of the physical film.
One last cinematic trick at play here is the use of subliminal images. In the scene where Tyler describes his projectionist job, we learn that he likes "splicing single frames of pornography into family films." This happens in Fight Club, too.
The film's final shot is a less-than-subliminal shot of a penis, right before the final credits. And there are subliminal flashes of Brad Pitt multiple times before his character actually appears on screen.