Not since "The Sixth Sense" has there been a movie that made viewers want to go back to see what they missed the first time as much as "Memento."

Not that the two movies share much in common. While the former was a psychological horror-thriller that drew in some families, despite its PG-13 rating, writer/director Christopher Nolan's crafty noir-esque thriller is decidedly a more R-rated affair.

And even though it's a bit harsh in terms of violent content and it's liberally sprinkled with four-letter words masquerading as dialogue, it's also one of creepiest pieces of filmmaking in recent memory — one that has its own peculiar way of sneaking up on viewers and then jolting them when they least expect it.

Equally surprising is the ease with which newcomer Nolan takes what seems to be a complicated, even confusing, plot and makes it seem crystal clear — at least when he wants to. (Much of the film's appeal is in its rather murky characterizations.)

Even more astonishing is the fact that he does so by shattering the usual, forward-moving, linear method of storytelling; he tells this story in reverse, so that you already "know" what happens at the end, with motivations for events and actions revealed gradually along the way.

The film's title obliquely refers to the few earthly possessions of Leonard Shelby (Guy Pearce), a thirtysomething fellow who has suffered some sort of trauma that has damaged his short-term memory. As the film begins, Leonard wakes up in a rundown hotel room, wondering how he got there and just what he's supposed to be doing. So he tries to reconstruct his recent past, relying on snapshots and quickly scribbled notes just to remember people he's recently met, as well as their relationship to him.

Bizarrely enough, he's also tattooed his own body with horrifying clues about the rape and murder of his wife (including one that states "John G. raped and murdered my wife. Kill him!").

Needless to say, he's unsure about whom to trust. There's the rather squirrelly Teddy (character-actor Joe Pantoliano), who claims to be his best friend — despite evidence to suggest otherwise. And the same goes for barmaid Natalie (Carrie-Anne Moss), who appears to be helping him at times and hindering him at others.

In fairness, that's about all that can be revealed of the plot without spoiling a few of the numerous surprises.