MementoMemento is a film written and directed by Christopher Nolan based on his brother Jonathan's short story Memento Mori. It stars Guy Pearce, Carrie-Anne Moss and Joe Pantoliano. The film was released in 2000 to widespread critical acclaim and received a Golden Globe (best screenplay) and two Oscars (best screenplay, best editing) nominations.
The movie consists entirely of an intricately woven pattern of flashbacks. The black and white sequences progress chronologically forward. The color scenes are arranged in reverse order. Thus the opening (color) scene of the movie is actually the last thing that happens in the story. In order to make it more jarring and accentuate the notion that color scenes run backwards in time, this 'opening scene' is shown in reverse motion.
Warning: Wikipedia contains spoilers
Leonard, played by actor Guy Pearce, is a man afflicted with a form of brain damage (severe anterograde amnesia, also called "anterograde memory dysfunction") after a struggle with a man who broke into Leonard's home and raped his wife in February 1997. Though his affliction keeps him from being able to form new memories, Leonard seeks revenge; to wreak this revenge he must keep notes on even his own life, tattooing himself with important clues and keeping photos of important people and objects in his life, including his car.
Lenny was a ruthless and clever insurance investigator whose first case involved a Sammy Jenkis, a victim of short-term memory. He determined to prove that the man was faking his memory loss and convinced the insurance company to cut off Sammy's insurance benefits.
In an act of retributive justice, Lenny becomes afflicted with the same condition and loses both his memory and his wife.
Two junkies break into the house of Lenny and his wife and rape her. They didn't realize that she didn't live alone, and one is shot by Lenny. The other knocks Lenny off-balance, and Lenny suffers a concussion.
The concussion gives him short-term memory loss. He can't keep anything in mind more than 15 minutes. But somehow he becomes aware of his condition and begins to exploit it.
He writes himself notes. He has a whole system of notes, including Polaroid photos in his pocket, an elaborate map on a motel wall, and tattoos all over his body.
Lenny's wife survives the attack, but is distressed over Lenny's memory loss. She can't bear the feeling of being overlooked; Lenny can't remember anything recent in their relationship. She determines a unique and potentially fatal way to deal with this.
She 'tests' whether he's faking the memory loss (just as Lenny did with Sammy), by repeatedly asking him to give her a shot of insulin for her diabetes. She tricks him by setting the clock back. Perhaps she figured if he really loved her he would 'snap out of it'. Or maybe she decided she didn't want to live if she couldn't have his love. Lenny gives her she insulin shot repeatedly, and she dies of an overdose.
Lenny, confronted with his wife's death at his own hands, refuses to believe it and enters a mental hospital. He grows to distrust the doctors, begins keeping a secret diary, and begins a project to "condition himself" (his words) to form new memories.
He chooses to 'remember' that the junkies who attacked his wife also murdered her. He makes it his life's ambition to track down "the man who murdered my wife" and get his revenge. Ironically, he himself is the man who killed his wife, and the revenge he exacts is horrible: he condemns himself to a lifelong abyss of crime.
A cop named Teddy, who was assigned to investigate the death of Lenny's wife, befriends Lenny. He helps him track down a man named John G. who was the other junkie from the break-in and rape. Lenny murders him, as Teddy watches and photographs the scene.
Although Lenny carries the photo with him, he can't remember committing the act of revenge. He continues his 'search' for the 'man who killed his wife' -- a search that corrput Teddy decides to put to use for his own purposes. He gets Lenny to murder drug dealer Jimmy Ganz.
In a crucial plot twist, both comedic and dramatic, Lenny decides to put on Jimmy's clothes and steal his Jaguar and his $20,000. But he is fooled by a note from Jimmy's partner girlfriend Natalie, which he finds in the pocket of Jimmy's designer suit. He meets her at the bar where she arranges drug deals for Jimmy.
Natalie recognizes Jimmy's car and suit and is suspicious. Lenny mentions his memory problem, and Natalie recalls hearing about his condition from a cop who was looking for him (not Teddy, though, whom she's never seen). She tests Sammy's memory in a sly way involving beer and spit.
She tells Jimmy's partner Dodd that Lenny has Jimmy's car. Dodd finds him driving around town in the Jaguar and gets the clueless Lenny to stop. A confrontation ensues and Lenny gets out of the car and runs; amusingly, Lenny forgets why he's running, spots Dodd and then starts chasing him. A gunshot from Dodd convinces him to start running away from him, and somehow he finds the car and rockets off.
He breaks into Dodd's motel room and decides to wait for him there, but forgets this and takes a shower. Dodd comes into the room, and Lenny warily turns off the shower. When Dodd enters the bathroom, Lenny suddenly jumps him and knocks him over the head with a bottle. He ties him up, stuffs his body in a closet, and calls Teddy for help. But then he lies on the bed and forgets what he just did!
Teddy comes over, hears Dodd struggling and agrees to help Lenny get rid of him. In one of this intricate movie's few plot holes, Dodd inexplicably agrees to leave town (he could have simply come back 15 minutes later and shot Lenny).
Lenny goes to Natalie's house and confronts her about Dodd, referring to his note: "Dodd - get rid of him for Natalie". Relieved that Dodd is out of the picture (there's that plot hole again), she decides to "help" him by looking up John G.'s license plate -- which is actually Teddy's license plate which Lenny had tattooed on his thigh right after murdering Jimmy.
Lenny is astonished to discover that the John Edward Gammel on the motor vehicle info is the Teddy from his own notes, and Lenny then murders him. Not that he'll remember it, of course.