Memento is a psychological thriller and mystery that was released in 2000. It was one of the first movies of famed director Christopher Nolan. The structure of Memento is very different from most films. It appears as if there are two different stories being told; one version is in black and white and is told in chronological order. The other version is in color but it is told backwards. The two stories meet in the middle of the film.
The film tells the story of Leonard Shelby, played by Guy Pearce. Leonard has lost his memory and must piece together the events of his past by notes and clues that he left to himself. The movie opens with Leonard waking up in a hotel room after his wife has been murdered. Two men murdered his wife and Leonard killed one of them but the other escaped. The police do not believe that there was a second attacker but Leonard is convinced. Leonard begins to perform his own investigation which is hampered by his loss of memory.
There are many different methods that Leonard uses to try to job his memory and solve the mystery of his wife's murder. He has a tattoo of a license plate number on his arm which he suspects belongs to the murderer. He meets the suspected murderer's ex who agrees to help him. She runs the license plate number. Leonard continues to find weird clues that he left to himself. He finds a photograph of man and a note that he wrote to himself, telling him not to trust the man. He ends up discovering the man's real name and realizes that he is the second attacker.
The story follows another man in the other segment. We see Leonard actually kill a man and swap clothes with him. He also takes pictures of the man's body. Leonard is told by Teddy, another man, that he is confusing his memories with memories of a con man named Sammy. Teddy tells Leonard that his wife survived the attack but died of an insulin overdose. Teddy tries to tell Leonard that he is doing all this on purpose, leaving himself clues so that his life has meaning. Leonard is disgusted with this idea and he burns the picture he took of the dead man's body. He then drives off and tattoos Teddy's license plate number on himself. This is the point where the stories converge.