Memento

Memento is the reason I have trust issues. In every new scene, the idea we had of a character was being warped from what it was in just a few scenes before. It was like one plot twist after another. The editing of the film is what ensures this. Had the movie been shown chronologically correct, it wouldn't be interesting, just a man hunting down all the John Gs he can find. All the plot twists and character warping come from the film being shown backwards.
I spent a lot of thinking time figuring out how the film was being shown, so I want to get it down in writing. Each new colored scene ends where the scene before began. In other words, each new scene is chronologically one step before the scene it follows. To make things more complicated, mixed into these colored scenes, are black and white sequences of (chronologically) the first scene. If the film was shown in order, this scene would be the first one you see. The black and white sequences are shown normally (not backwards) so that at the end of the movie (or the middle of the story), the B&W and colored scenes meet up. It's all very confusing but I think that it gives the viewer a sense of how the main character feels. Lenard can't make new memories so whenever his train of thought starts over again, he's disoriented and lost. That's how the editing in this film constantly made me feel, I had to quickly pick up on the surroundings and figure out  the plot from there.
It helped that the storyline was just as twisted as the editing. All the lying and deception added to how the backwards editing was able to reveal things layer by layer. This can be seen in how the viewer is supposed to think about Teddy throughout the movie. We begin by seeing his death and all the clues that would point to him as being the killer of Lenard's memory and his wife. This initially puts Teddy as the antagonist, but as the movie goes on it is later revealed Teddy was a police officer, trying to help Lenard feel satisfied by killing the actual murderers and also just using him to kill a drug dealer. Natalie is another character whose image gets shifted as more of what Lenard doesn't remember about her is revealed. At first, she seemed like a friend trying to help Lenard find the killer, but we learn that she too is just taking advantage of Lenard's disability for her own gain.
A part where the editing could've been better was when the story of Dood was being explained. I found that part confusing and and had to do some online digging to figure out how he played in the story.
Another film that relied heavily on the use of editing to reveal the story is Fight Club. Both leads in Memento and Fight Club suffer from a mental disability, but in Fight Club, we don't know this until the end. The movie's editing drops hints throughout the film about the character's mental state and how it changes when he meets Tyler Durden.
The editing of a movie makes it what it is. The way something is cut up and presented to us can totally change how we perceive it.