Oh, and don't read the back of the box or try to find out information on it -- that'll take away from the experience of the film. (Would you have wanted to know the end of Sixth Sense or Fight Club before seeing them? The story and structure of Memento are like that.)
Still here? OK. My brother pointed out a couple of things at another forum that I was amazed at. I just verified the first one, and hadn't thought about the second until he pointed it out. They're great insights, and they do indeed make you wonder...
The forum he used to point them out is here, in the second post down.
I'll save you from going to that server, though, if you don't want to head over there.
As for "Memento," I agree this was one of the best movies of last year. I do have two things about this film that I enjoy pointing out to people. If you haven't seen the movie, spoiler alert, I'm about to discuss some major plot twists, so do yourself a favor and stop reading and go rent it right now!
Okay, here goes. Towards the end of the movie, when Leonard finishes his black-and-white-flashback story about Sammy Jankis, we see the actor who plays him, Stephen Tobolowsky, sitting in a mental institution looking upset. Watch closely. Right at the end of the shot, there's a foreground cross (somebody walks between the camera and the subject) and at the end of it, there are two final frames before it cuts back to Leonard telling the story, and in them, Tobolowsky has disappeared and Guy Pearce is sitting in his place in the same position. A subliminal clue that Leonard is really talking about himself. I actually caught this in the theater and nobody believed me, but later I went frame-by-frame on the DVD, and there it is, plain as day.
The other thing is a possible flaw that I caught. At the very end of the movie, Leonard angrily scrawls himself a note, "Tattoo: Fact 6," followed by Teddy's licence plate number. How did he know he was on Fact 6? He didn't strip naked and count the other five.
The reason I call this a "possible" flaw is because everything else in the movie is arranged so smartly, I'm not completely convinced that this was an accident. It might be a suggestion that Leonard's mental state isn't as bad as he makes it out to be. We're already shown that he embraces it and works with it in order to trick himself to stay in that place where he's searching for the killer. Maybe part of that involves exaggerating his symptoms, even to himself.
When you follow this little observation, it leads you to a totally different interpretation of every one of the movie's events. And that, my friends, is good storytelling.
Damn. Now that I know those things, I wanna see the movie again...