From iconic scenes that were originally billed as something else entirely to actors that were almost never a part of the shows they are so well-known for, cinema is as rich in back stories as it is in films.

Below are 10 of the most surprising back stories in cinematic history. If you think you know your favorite films, chances are you will be shocked to find out what went on behind the scenes.

1. A.I.: Artificial Intelligence (2001)

In the world of movies there are many instances when a great film is based on a short story. Many of Stephen King’s short stories have been made into films or film anthologies.

But most people were unaware that the 2001 flick “A.I.: Artificial Intelligence” was also based on a short story.

The futuristic film follows the story of a young boy and an eclectic mix of android characters.

Steven Spielberg’s epic about robots in a futuristic society is based on the short story, “Supertoys Last All Summer Long”. But the story doesn’t end there. As it turns out, Spielberg decided to go ahead and make the film to fulfill one of the last wishes of a famous director who also happened to be a close friend.

For over a decade the project was an ambitious dream for legendary director Stanley Kubrick. After his death, Spielberg picked up the project out of respect.

While the story itself is a bit of an acquired taste for some, and the movie was beautiful and strange at the same time, the fact that Spielberg would take on a project of this magnitude to honor a friend and great director is a touching back story that makes it all the more touching and human.