At best, Memento is a cleverly presented psychological thriller that shows some of what is mean by the mention of the deceit of the heart in Jeremiah 17:9. At worst, it proclaims the inherent meaninglessness of all things without even hinting at "the conclusion of the whole matter" found in the last two verses of Ecclesiastes.
The cleverness in the presentation of Memento is that as the movie proceeds, it unravels in reverse chronological order. In other words, we begin with the end of the story and end with the beginning of the story.
Beginning with the end of the story, we see the main character kill someone. Then we are taken back in time, to just minutes before the killing sequence, and shown another sequence unfold until it reaches the killing with which the movie began. The rest of the movie is a repetition of going back in time a matter of minutes or hours or days and then watching what unfolds until we reach the beginning of the sequence we just saw.
We are drawn in because we find that the main character, Leonard, is on a mission to avenge the rape and murder of his wife. Our desire for justice embraces his mission. We want to believe that he had executed justice by killing the man at the beginning of the movie.
The only problem is that he has, as he puts it, a "condition" in which he "can't make any new memories." That is, he cannot retain memory ever since the horrific night when two men broke into his house and raped and murdered his wife. In the ensuing struggle, he managed to kill one man but was struck in the head and knocked unconscious by the other. The blow damaged his brain so that now he forgets his name, what he is doing, where he is, etc., after mere minutes.
To deal with the impediment of having no short-term memory, Leonard has developed a system not of "memory," but of "instinct." Since memories are an "interpretation, not a record," he relies on "facts" - tattoos, pictures, strategically placed notes - and ties them all together with "instinct." Some of the most prominent tattoos across his chest are "John G. raped and murdered my wife" and "Find him and kill him." Also written on his left arm are "The facts:" then, underneath, "Male," "Drug dealer," and a license plate number. Leonard uses all of these "facts" to keep his purpose of just vengeance honed and direct.
Leonard does, however, remember things before that night when his wife was violated and murdered and he lost his ability to retain short-term memory. One of the main things he does remember is the story of Sammy Jenkis. Even though he can remember this story, a tattoo on Leonard's body still testifies to the memory. "Remember Sammy Jenkis," reads the tattoo. As the movie unfolds Leonard tells us (via voice-over) the story of Sammy Jenkis: Before Leonard lost his ability to retain short-term memory, Sammy Jenkis had similarly lost his; and it was Leonard's job as an insurance company investigator to determine if Sammy and his wife were eligible for insurance payments. They were denied payments when Leonard's investigation ended with the conclusion that, "Sammy should be physically capable of making new memories."
In Leonard's view, Sammy simply didn't have the right system to make him a functional human being. But now Leonard, with the same problem as Sammy, relied upon an effective system, one based not on fallible, interpretive memory, but on "facts" - strategically placed notes, pictures, and manuscripts.
In the end, Leonard comes to a new conclusion concerning Sammy's "slight look of recognition, but swearing he can't remember" contradiction. It was this apparent contradiction that had originally prompted Leonard to officially state that Sammy should be "physically capable of making new memories," and was therefore ineligible for insurance payments. But "I was wrong about Sammy," Leonard tells us, "Now I know you fake it, you create your own truths."
Leonard comes to this conclusion at the end of the movie, which, remember is at the beginning of the story that eventually culminates in Leonard's killing of a man. Teddy is the name of the man Leonard kills. Throughout the movie, we have no idea if Teddy is good or bad, friend of foe. He seems a little shifty, being, as far as we can tell, a somewhat dishonest cop. But we really don't know what Teddy's intentions are, even though we instinctually trust Leonard's distrust of Teddy, a distrust based on a "fact," that is, a Polaroid picture taken of Teddy by Leonard. On the Polaroid, Leonard had written these words: "Don't believe his lies."
We should note that throughout the movie Leonard takes Polaroids of people to "remember" them. After taking a picture, he writes notes on the picture to help himself remember things about them. Then he relies on the "fact" of the picture, and on the "fact" of the note on the picture to aid him in his constant minute-by-minute decisions.
At the end of the movie, having reached the beginning of the story, we discover when and why Leonard writes what he does on the Polaroid "fact" "Teddy." Leonard writes, "Don't believe his lies" on the Polaroid after he kills a man (who is, by the way, both "male" and a "drug dealer," two of Leonard's tattooed "facts") and has a distasteful conversation with Teddy. Apparently Teddy and Leonard were in cahoots, or Teddy deviously used Leonard to accomplish the murder, or both.
In their conversation following Leonard's killing of this man, Teddy tells Leonard that he has simply been trying to help him find and kill "John G.," the violator and murderer of his wife. What's more, says Teddy, this man you just killed is "John G."! But Leonard refuses to believe Teddy. Teddy then modifies his story and says that, really, "the real John G." is already dead, that Leonard has already hunted him down and killed him with Teddy's help. Teddy tells Leonard that one of the pictures he has, a picture of himself, was taken by Teddy just after he had killed "the real 'John G.'" "See how happy you look?" says Teddy in reference to picture. Leonard still refuses to believe Teddy, and Teddy replies that, yeah, "It didn't stick, just like nothing ever sticks," but "Cheer up, there are a lot of 'John G.s' out there卙eck, even I'm a 'John G.'!" Teddy then gives Leonard more "consolation": "So you lie to yourself to be happy - there's nothing wrong with that, we all do it. Who cares if there's a few little details you'd rather not remember." But Leonard still vehemently disagrees with Teddy, takes Teddy's keys and gun, and sits in his vehicle, brooding over what Teddy had said. "Do I lie to myself to be happy? In your case, Teddy, I will."
As Leonard says these things to himself, he takes Teddy's picture out of his pocket and writes, "Don't trust his lies" on it. Then he takes the picture of the body of the man he had just killed (he had taken a picture of this immediately after he done it) and the picture of himself after killing (what Teddy had told him was) "the real John G," and burns them. Then he gets into the dead man's car, drives away, and slips into a nihilistic reverie: "I have to believe in a world outside of my own mind. I have to believe that when my eyes are closed, the world's still there. Do I believe the world's still there? Is it still out there?" He closes his eyes. "Yeah." So he tell himself as he drives to the tattoo parlor to have Teddy's license plate number tattooed on his arm, under "the facts."
So what is the conclusion of the matter? "God created man good, but he has sought out many schemes." "The heart is deceitful above all things and desperately wicked; who can know it?" In other words, we are all like Leonard insofar as we try to create "the right system," based on "fact" or "instinct" or both. We all try to find meaning in things other than absolute submission to Jesus Christ our only Lord and Savior. And we all blind ourselves to the horror that this entails, to the horror that would drive us insane if we truly saw it in its entirety - adrift in an infinite sea of chaotic nothingness, infinitely far from Him, murdering those around us in the name of "certainty," "meaning," even "righteousness." "All my righteousness is as filthy rags." What wretchedness when we even need to repent of our righteousness! And yet we still want to be hypocrites, outwardly beautiful, but inside full of dead man's bones. We still struggle to maintain our living death. We do not want to pass over to Life more abundantly. Is it any wonder that we must truly die before we can truly live? "For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live" (Romans 8:13).