Memento is a movie about a guy named Leonard Shelby, who is trying to solve his wife's murder. At his disposal is a camera, tattoos, a sharpie, and a cunning but annoyingly damaged brain.
This contains numerous spoilers... so if you're really interested in this movie you should probably stop reading.
Memento focuses on a man named Leonard Shelby (who is the most badass person with that name in the history of anything). He used to be an insurance claims investigator (these are the people who make sure that if you say you're injured and need insurance money, you're telling the truth). He is working on a case where a man is diagnosed with anterograde amnesia. But then his house gets broken into by two burglers, leaving his wife dead, and his brain not working so rightly. So now, he's chasing down the man who killed his wife (oh, because he killed one of the two attackers in the original altercation).The problem is he's got this pesky little brain issue, called, you guessed it! Anterograde amnesia. It's fancy sciency talk for "no new memories can be saved". Kinda like how I typed up this whole article and then accidently clicked back without saving and BAM, I had to start over. Except that's how his brain works, and he clicks back every couple minutes. And doesn't learn how to click save every now and then.
So Leonard, in all his manly fury (exceptionally manly because his last name is Shelby) tattoos messages on himself and takes polaroids and labels them with his trusty sharpy to keep himself on track. But the story takes place in two timelines, with one in colour moving backward (beginning with Leonard killing the attacker and then showing the search for the heinous killer) and another in black and white moving forward, where they reconvene at the middle point in the story, at which point everything you'd already seen will occur.
This kid probably shouldn't be watching Memento
After his series of bizarre events (involving drinking a beer that a girl spit into right in front of him a minute before; killing some dude named Jimmy and stealing his car and clothes, later believing them to be his; etc.) it's insinuated that Leonard actually killed his wifes killer over a year ago, and just doesn't remember it and will continue his quest to get revenge over and over again, even if he succeeds everytime. And the biggest peice of evidence he's got to go on is the knowledge that the killer's name is John G.
If your name is John G, this is the last thing you see before you die via bullet to brain.