Making a movie is pretty difficult, and between all the factors that go into it, there's plenty of chances for something to go wrong. Sometimes, that means having to do multiple takes and spending days on difficult scenes. Other times, like in these 10 cases, it leads to amazing moments that we remember forever.
1) Zoolander - "But why male models?"
Ben Stiller forgot his lines and accidentally repeated one he'd already said, but in the end it just made Derek Zoolander even more of a lovable idiot.
2) Midnight Cowboy - "I'm walkin' here!"
After getting fed up with traffic delays from the filming of the movie, a New York cabbie sped past traffic... right into Dustin Hoffman. The result is the singularly most iconic scene from the movie.
3) The Lord of the Rings: The Fellowship of the Ring - Knife throwing
During the fight between Aragorn and Lurtz, the actor playing Lurtz was only supposed to pretend to throw the knife at Viggo Mortenson. However, the knife actually left his hand (you can see a split-second of his "oh s***" face if you look carefully), and, thinking quickly, Mortenson actually DEFLECTED IT WITH HIS SWORD.
4) Being John Malkovich - "Hey Malkovich, think fast!"
The scene just called for cars to drive by John Malkovich as he walked away angrily, but a few extras hired for the scene had snuck beers on set and got too rowdy. The can throw and look of surprise and pain on Malkovich's face are completely real.