Memento-Narrative theory and Character roles

The narrative of Memento does not follow any traditional Hollywood narrative pattern. The film follows the story of Leanord, a man who has lost his short term memory and is confused as to how his wife dies but believes that the man to blame is a man by the name John G. The film is different to traditional narratives as it follows no chronological order.
The narrative pattern consists of the same story line split into 2 halfs and played alongside each other until they eventually meet, the way we are shown this to happen is through the use of colour, the images in black and white are of the story line in the present and the film in colour shows the film going in reverse, showing flashbacks of his past. this is to give us the perspective of his life, and not being able to figure out what happened.
Aswell as there being no real trraditional narrative the character roles are also very unusual and it is very hard to distinguish throughout whether or not anyone is the villain and if anyone is the hero, the only character role we can be sure on is that there are definately false heros throughout. Leanord is the main character has lost his long term memory. Teddy is shown frequently throughout the film and appears to be one of heroes, he is constantly helpful to leanord and although he can seem quite a suspicious character at times he never is actually hurtful towards him. We then get introduced to natalie, she goes from role to role, at first she seems like the donor she constantly gives lennie clues and information to write down, she then continues to be nice to him and turns into the hero but gradually takes advantage of him and becomes the false hero. Leanord is told about a man called sammy jenkis he is told that sammy jenkis was a con man and that lennie confuses parts of his life with the life of sammy jenkis. Sammy had no wife and lenaords wife survived the attack that led to him losing his memory and thinking his wife had died. It is actually lennies wife that was diabetic and it was her that was killed by an insulin overdose from leanord. We could say that Sammy Jenkis is the doner in the stroy because he gives leanord a reason for trying to find the 'John G' character, although he may be getting confused this is the only motive he had.