Trivia: When Cobb asks Ariadne to draw a maze, she draws several that are "too easy." She then draws a circular maze which Cobb deems difficult enough. However, this maze is actually impossible to solve. If you pause and try, you will see it is just a dead end. [Technically a mistake, but the movie needs to be paused, so doesn't really count. Worth a look regardless.]. (00:25:40)
Trivia: Christopher Nolan's cousin Miranda has a cameo as an air hostess.