7 Despite popular belief, the idea of Inception was first conceived in 2001 by Nolan, a year before The Dream of a Lifetime, a Donald Duck comic, was published.

In the comic, Uncle Scrooge’s dream gets invaded by the Beagle Boys using a device. Similar to the movie, they try to extract the lock combination, behind which Scrooge hides his treasure. Donald Duck then attempts to stop it and rescue him by entering the dream as well.(source)

8 Cobb, the name of the main character, is the same name Christopher Nolan used in his first movie Following (1998) for one of the main characters.

9 The name Cobb is also a reference to a famous architect Henry N. Cobb. He designed many skyscrapers, the kind of buildings Mal and Cobb loved to build and live in the limbo they created.

10 In Japan, the movie is broadcasted on television with the number of the dream level displayed in the corner, to prevent confusion while watching.

11 Brad Pitt and Will Smith both turned down the role of Cobb which eventually went to Leonardo DiCaprio.

12 The entire movie was filmed without using any second unit, as were all of Nolan’s movies.