I just saw Memento... and I'm stunned.
I could really identify with the emotions in this film. The inability to understand one's surroundings, the demand for fast action beyond your capabilities, the claustrophobic feeling that everything is closing in on you, the unstoppable feeling of horror that just won't go away... wow.
One of the most gruelling parts of the film is when the protagonist talks about how he's unable to heal because he can't experience time. His wife is gone and there's nothing that he can do to come to terms with that fact. Every time he wakes up, it's like he just found out that she was killed for the first time. The last available memory to him is that of his wife dying in front of him while he's helpless to do anything about it.
The only thing that the main character has left are his long-term memories of her before the accident. In one scene, a friend implores him to close his eyes and remember her, because that's the only time that he's ever happy. The way that he clings onto little details (even things that used to annoy him, like the way she used to say his name) reminds me of how I recall the last time I was happy while in the middle of a relationship with someone. The only problem is that, towards the end, even those memories, the only things that he has left, are drawn into question. He's becomes unsure of how they even happened and of how much he's constructing after the fact. That's really scary.
Like some critics, I was left a little unsatisfied by the ending. I'm still not completely sure what happened, but maybe that's a larger metaphor for the screwed up way that memory works. You're left without a clear picture of the world. The only thing you have is the blind confusion of the present moment where nothing is certain.