The Thirteenth Floor
Nolan worked on the script for nine to ten years. When he first started thinking about making the film, Nolan was influenced by "that era of movies where you had "The Matrix" (1999), you had "Dark City" (1998), you had "The Thirteenth Floor" (1999) and, to a certain extent, you had "Memento" (2000), too. They were based in the principles that the world around you might not be real."