I distinctly remember a scene in the movieInception when Cobb is testing Yusuf's custom made super sedative. He then abruptly wakes up and goes to the bathroom where he proceeds to splash his face with water and spin his totem. However, before the top can reveal whether he is in a dream or not, it is interrupted and knocked off the counter. Cobb then sees Mal in the reflection of the mirror. Surely Nolan made the scene in order to help the audience understand how Cobb is starting to have trouble differentiating whatswhat's real from what isn't. But is there any definitive evidence to prove that the rest of the movie is not just part of a sedated dream he never escaped?