Here's something to remember about Memento. Look for the shot near the end when Leonard Shelby (Guy Pearce) is lying in bed with his wife. Watch for the tattoo on his chest pec that says, "I did it." It's a clue to one of the many secrets of Christopher Nolan's fascinating neo-noir. And it's the kind of clue that opens up more mysteries than it solves.

Leonard (don't call him Lenny) is a former insurance adjuster, i.e., one of those guys who investigates claims to prove that the company doesn't have to pay on them. One night his wife was raped and killed, and he was knocked unconscious. Ever since then, he has suffered a severe shortage of short-term memory. Searching for the murderer of his wife, whom he knows to have the initials J. G., he photographs every person he interviews and every site he visits, and annotates the stills to keep re-informing himself of what's going on in his life. They are like little news bulletins from a succession of former selves. But like many news bulletins, they mislead as much as they inform.

Helping him in his task are two unsavory people: the chipper Teddy (Joe Pantoliano), a mysterious fellow who keeps popping up at unexpected times like a hardy salesman; and Natalie (Carrie-Anne Moss), a shady bartender with a tendency to wear biker fashions and bloody lips. She claims she can tell Lenny about the man who murdered his wife if Lenny will take care of a guy who she suspects offed her drug dealer boyfriend. In the course of Lenny's forays into vengeance, he makes a series of discoveries. Thing is, he doesn't remember any of them. And there is a strong possibility that his two newfound friends are using him and his condition for their own ends.

Oh, and by the way, did I forget to mention that the movie is told backwards?

The narrative of Memento comes in chunks of five minutes or so, each one set five minutes before the previous chunk, and each representing the complete length of Shelby's memory capabilities. Thus a broken car window in the first sequence isn't explained until the eighth. A busted lip in one sequence is explained in the next, which actually happened before. It's not as confusing as I'm probably making it sound, and what's remarkable about Nolan's narrative technique is how much it puts you into Shelby's consciousness. Suddenly, the world looks very fragile and everything seems both new and ominous. While these strange "flashbacks" are going on, there is what appears to be a present time sequence in black and white that explains a lot of what's going on. Nolan wrote the screenplay based on his brother's short story, but he has been down this path before: His one previous movie, the promising Following, also deals with betrayal set within a fragmented story structure.

There have been so many memory loss movies lately, you'd think there was an epidemic of this rare disease, with Oliver Sacks running from movie to movie with emergency Polaroid photo kits. But Memento is actually funnier than Dana Carvey's one-note movie Clean Slate, and moodier than Tom Tykwer's Winter Sleepers.

Memento has a lot of starch in it; the film sticks with you for days, as you rehearse it over and over in your mind. It's also a movie so good that you almost fear a critical backlash against it. You come out of it feeling almost resentful at how good it is, and given that almost everyone is an aspiring filmmaker these days, this resentment is unvarnished jealousy. But this reviewer is pure of spirit, or at least spite: I may have seen a better film so far this year than Memento, but if I have, I've forgotten it.