This year marks the 15th anniversary since "Fight Club" debuted in 1999.
The movie tells the story of how an office worker (Edward Norton, simply known as "The Narrator") meets an eccentric man named Tyler Durden (Brad Pitt), and how both start a secret fight club that evolves into an insane underground cult.
The big twist is that Tyler is actually not real. He's a figment of The Narrator's imagination.
When the movie first came out in 1999 this was a shock to audiences. But if you rewatch the film, you will see that director David Fincher hid a bunch of clues throughout the film that actually gave away the ending.
Fincher did this in a few ways, one by subliminally flashing Tyler on screen for a brief second.
Fincher did this a few times before The Narrator even "meets" Tyler. Another clue was how Fincher hid Tyler in a hotel commercial that The Narrator is watching. You can see Brad Pitt in the front all the way to the right. Other clues are a bit harder to find.
For example, after The Narrator meets Tyler he calls him from a pay phone. Tyler doesn't answer, but calls back. However, if you look closely you'll see the pay phone says "no incoming calls allowed," showing that Tyler can't call back because he isn't real.
Later in the film, Tyler is driving down a highway when he purposely crashes a car to teach The Narrator to let go. But after the car flips upside down, Tyler gets out on the passenger's side and crawls over the car, pulling The Narrator out of the driver's side. Showing that The Narrator was driving the entire time.When "Fight Club" first hit theaters 15 years ago, it bombed, making just $37 million domestically on a budget of $63 million.
But thanks to small hidden details like these, the film went on to do very well on DVD, selling over 6 million copies, and has gained a huge cult following.
Watch the original trailer for the 1999 film below: