There are at least two good reasons why Hollywood is so fond of movies about memory loss. One is that the movies are always and inevitably tempted by voyeurism, and exotic illnesses or injuries, including psychological ones, promise voyeuristic thrills a-plenty. The other I think has to do with visual paradox. The movies are supremely realistic — surrealistic, you might almost say — in their capacity to look more like life than life does. Human life is always writ large on the big screen. But life as most of us experience it depends utterly on knowing who and where we are on earth, on placing ourselves in relation to the rest of the world. The central task of the mise en scène is to place people in some context. But what if the people themselves don’t recognize their context? This is interesting to an audience in one way if they know what the characters don’t, which is the case in most such movies, and in another way if they don’t know either and have to figure out the context as the characters do, as in Memento or Mulholland Drive. A movie like The Bourne Identity offers a mix of the two.

But memory is also shorthand for identity: we are our memories in a way that everyone instantly understands and that the movies have been happily exploiting at least since the classic amnesia flick, Random Harvest of 1942. We all instinctively feel that to lose our memory is to lose ourselves, though this is something about which audiences may often be expected to have mixed feelings. On the one hand, that is, America is the land of second chances. We like to believe that history is bunk because we don’t like being bound by it. Where fresh starts are a kind of national religion, memory-lessness, assuming that the other faculties remain more or less intact, is the ultimate fresh start. To those for whom the past is a burden there is bound to be something attractive about simply shedding it — though ethical questions may also arise where, as in the case of Eternal Sunshine of the Spotless Mind, something like "brain-washing" is going on. On the other hand, we are terrified by the prospect of Alzheimer’s disease, as it is naturally horrifying to think of ourselves as unable to recognize our loved ones or to remember the things that are most important to us.

Alzheimer’s itself makes a moving appearance in such films as Iris, about the English novelist and philopher Iris Murdoch, the Argentinian film Son of the Bride (El Hijo de la Novia) and the forthcoming adaptation by Nick Cassavetes of a Nicholas Sparks novel, The Notebook. But it is hard to do very much with such a theme except to show, with the help of flashbacks to better times, the pathos of what the disease can do to destroy a person with a vibrant presence — especially, as in all three of these cases, a woman — and make her into a hollow shell of a human being. There are also a number of movies that explore the idea of people getting a do-over in life, the best of them all being Groundhog Day of 1993. A similar idea occurs in Sliding Doors and Twice Upon a Yesterday, also known as The Man with Rain in His Shoes, both of 1998 and Me Myself I of 1999. Except for Groundhog Day, these all have a certain fanciful and merely speculative quality to them that makes them seem insubstantial. All, however, are more or less alert to the moral implications they raise, which forms a link with the school of films which explore the ambiguity of our feelings towards our memories by using memory loss as metaphor.

In this year’s 50 First Dates, for example, the hero played by Adam Sandler is a womanizer who lives in Hawaii and dates only tourists. They are presumably looking for a good time and often want to forget about it and him when they return home, as he always forgets about them. He is a reminder that Don Juan is the prototypical amnesiac. But one day he meets a local girl, Lucy (Drew Barrymore), to whom he is unaccountably attracted and who has lost her own short term memory because of an accident. Suddenly the man who specialized in forgetting women, and making them forget him, finds himself in love with a woman who can’t remember him from day to day. In a way this can be seen as a condign punishment, but in another way — and this is how Mr Sandler, who does not specialize in humility and contrition, plays it — her condition suits him down to the ground. He is doing what he has always done, attempting to charm a new girl every day, at least so far as she is concerned. From his point of view, the triumph of the fresh conquest is presumably undiminished because she is the same girl.

When, in Shakespeare’s Winter’s Tale, King Leontes of Sicilia suddenly realizes the devastation he has caused by his unreasoning fit of jealousy towards his wife, Hermione, the first resolution he can think of to repair the damage is to "new-woo my Queen." It points up the moral that there is to be found in the more optimistic take on the situation in 50 First Dates. In fact, it could be said that Lucy is living every woman’s dream. She can never be taken for granted or ignored because her young man has to new-woo her every day. Some women might be tempted to think that it would almost be worth sacrificing their memories for such a happiness. And of course the happy couple in this movie are not unaware that they are — or at least that she is — uniquely favored by being able to enjoy the thrill of their first kiss again and again. At times we have the feeling that the movie is tending towards mere wish-fulfilment, as so many movies these days do.

The scenario of 50 First Dates was pioneered by a movie called Clean Slate of 1994 which starred Dana Carvey as an amnesiac private eye trying to investigate a murder without being able to remember from day to day who he is or what he is looking for. A comedy, this proved to be rather a disappointment because it tried to do too much and was cluttered with irrelevant and not very comic material. There, amnesia was only a plot device, as it is in so many daytime soap operas, and a means of generating some laughs without any deeper significance. Yet feeble as it was, it also looked forward to Christopher Nolan’s much more ambitious Memento (2000) in which an amnesiac, played by Guy Pearce, is seeking revenge for the murder of his wife and has to write the various clues and leads he uncovers in hunting down the murderer on his body to be sure that he will remember them — and him. For his forgetfulness makes him a walking embodiment of one of the main moral problems with revenge, which is that by the time vengeance is accomplished neither the victim nor the villain are the same people they were when the initial offense took place.

Without memory, in other words, there can be no revenge. And so powerful is the urge for revenge in the hero’s case that he must keep it up as best he can with the very inadequate memory-substitutes of tattoos and post-it notes and polaroids. The problem with the film is that, in attempting to put the audience in the hero’s place by telling the story backwards, it comes after a while to seem merely gimmicky. The serious moral question of the morality of revenge is obscured by the mental exercise required just to work out the puzzle of sequence and causation in a story that is being told back to front. And there seems no place at all in it for those who, faced with its implied trade-off between memory and mental tranquility, would choose — as most of us surely would choose — to keep their memories even if we found that they bound us to an act of vengeance.

This question arises much more specifically and meaningfully in Atom Egoyan’s Ararat (2002) which concerns itself — along with too many other things — with the Armenian genocide in Turkey in 1915. There the forgetfulness is not primarily individual but collective. What does it mean to be the son or grandson or even great-grandson of those who actually suffered the original injury? In tribal societies, of course, the demand for revenge can easily span the generations, but you don’t have to be a primitive tribesman to recognize the uniqueness of the crime of genocide. If someone tried to obliterate your ethnic identity even long before you were born, is it not as much an injury to you as it was to your ancestors who were killed? The injury in such a case is two-fold: the individual who is killed, raped or maimed has a grievance against his assailants as human beings just as he would if they were of his own nation, race or tribe; but if he were killed merely for belonging to that nation, race or tribe, all who belong to it would also have a grievance. It’s hard to see where that grievance could ever end.

In Egoyan’s film the genocide is something that the protagonists strive both to remember and to forget, and the question of the ethnic obligation to remember is left up in the air. Like Clean Slate, the movie is too busy and loses itself in a welter of conflicting and complementary psychologies in the present day. But the fact that the actual massacre, only present in the form of a movie within the movie, is constantly fading into the background has its own significance. For like the backwards story-telling of Memento, it makes a nice analogue of the characters’ own forgetfulness and thus of the Heraclitean notion that the passage of time makes the essences of identity that revenge must believe in problematical. And yet this argument is really just a disguised tautology. Sure, if you take away memory, revenge makes no sense because identity has shown itself in forgetfulness to be fluid. But it is precisely memory that solidifies identity — and that few of us would wish to be without at any price if we could help it.

Without memory, in other words, we cease to exist as who we are and become only receptors of current data. And memory also alters as a result of moral information. One of the best recent statements of that idea is to be found in Alejandro Amenábar’s Open Your Eyes (in Spanish Abre Los Ojos) of 1997 — later remade in an inferior American version called Vanilla Sky with Tom Cruise. Like 50 First Dates, the film features a Don Juan figure, played by Eduardo Noriega, as its image of forgetfulness: a man who "forgets them as soon as he sleeps with them." He, like Adam Sandler, finally falls in love, but is stalked by a vengeful former girlfriend who can’t forget that he has forgotten her. She deliberately kills herself and horribly mutilates him in a car crash. He is left to seek by scientific manipulation a way to get back the past and the woman she took from him — only to find that when he does so he can’t tell the woman he wants from the woman who tried to kill him for not wanting her. Thus he becomes the victim of the kind of forgetfulness that had first made him a victimizer. In this film the moral implications of memory are much darker and much more fully explored than in 50 First Dates, but like that film it leaves some of the central questions it raises unresolved.

An even stronger contender for the Oscar for the best cinematic treatment of memory as metaphor is Eternal Sunshine of the Spotless Mind, which deals with a fictional doctor-scientist, played by Tom Wilkinson, who has developed a technique to brainwash two unhappy former lovers, played by Kate Winslet and Jim Carrey, so that they no longer have any memory of each other. The science is rather cheesy and Dr Who-ish, but the metaphor is much stronger. This is partly because Jim Carrey’s character, supposedly asleep throughout the movie as his memories are being erased, suddenly develops regrets and frantically tries to resist the process by finding hiding places for the memories he no longer wants to let go of. More importantly, when he has apparently failed in all but arranging in his dream for another first date, the two meet again and fall in love again. At that point an accident reveals to them that they have a history together which both have forgotten. As they listen to tapes of themselves describing their dissatisfactions with each other at the point where they have, so far as they can tell, only just met, they are granted a double perspective on their relationship, as they see the typically sweet, trusting, ever hopeful beginning and the typically sour, suspcious, desparing end simultaneously.

That love wins out over doubt and resentment seems only natural and right and a reminder that among love’s obligations is the obligation to keep fresh the memories that made us fall in love in the first place. This process is naturally the opposite of that employed by the forgetful Don Juan who is the master figure of our sexually licentious age. But in trying to conform to that model, the two lovers in Eternal Sunshine of the Spotless Mind discover that what they have been seeking is really a loss of self, even a loss of soul — which, as we remember, was also the fate of the original Don Juan, dragged down to hell by the ghost of the wronged woman’s father whom he had killed. Memory, that is, may carry with it the need for revenge, as in Memento and Ararat, but here it also carries with it the need for forbearance, hope and charity. Being who we are, who our memories make us, is no guarantee of being good, but it is a prerequisite to being at all.

Something similar is suggested by a movie that is in some ways even better than Eternal Sunshine. Where that film achieves its effects with the help of a comical mad-scientist and his louche associates, Wandafuru raifu (i.e. "Wonderful Life") or Afterlife (1998), by the Japanese director Hirokazu Kore-eda is set in that special twilight zone inhabited by movies about life-after-death where everything seems mad — but only, as we gradually learn to think, because the universe is saner than anything we are accustomed to on earth. Afterlife’s afterlife consists of a vast, Japanese-style bureaucracy in which the newly dead have to be processed by civil servants who gently lead them to the choice of their happiest earthly memory, in which they will subsequently live for all eternity. It emerges that the civil servants are the dead who cannot make up their minds and so condemn themselves to live in a kind of limbo, guiding others to the happiness that they have not the power to choose for themselves.

I wondered when I saw this movie if it had been influenced by one of the great under-appreciated films of the last decade, Kids in the Hall: Brain Candy (1996). Its premiss is that a giant pharmaceutical company has developed a happy drug called Gleemonix that makes you feel "like God is rubbing your tummy" and that it rushes into production before clinical trials have been completed. The effect of the drug is to summon up people’s happiest memories as a means of keeping them in a blissful state. But after the drug has become a runaway best seller, the people who had taken part in its early trials start to become catatonic. Like the dead in Afterlife, they are stuck forever in their happiest memories. But where in that film this position is heaven, albeit a very mysterious sort of heaven, it is hell in Brain Candy. The head of the pharmaceutical company, played by Mark McKinney takes the view that the comas of the drug’s victims are "acceptable losses." Of course, he adds, "you could take the narrow view and say, ‘Oh God! More coma victims.’" So he offers hospital care and big checks to the victims and a beauty contest: Miss Coma.

But the research team that invented the drug have learned to see that "People are supposed to be depressed sometimes. You can’t be happy all the time; that’s life." And so they decide to start "working on a cure for all this happiness." In this way the film also looks forward to Eternal Sunshine which is similarly persuasive that we have to hang on to the bad memories as well as the good. But the later film also goes on to suggest that the bad ones are somehow included in the good ones and are redeemed by them. Without them, with only happy memories, we would be like the catatonic victims of Gleemonix, imprisoned in ourselves. Perhaps, as in Eternal Sunshine, it takes the unhappiness to make us see ourselves as we really are, and as others see us. At any rate, this is the central idea of Afterlife which follows the progress of a Mr Watanabe (Taketoshi Naitô) who cannot choose his favorite memory because he claims to have no memories. In seeking to acquire some through the modern method of videotape records, he is stricken with remorse at the way he lived his life, and especially the way he neglected his devoted wife. Once again, evil is associated with forgetfulness, good with remembrance.

Mr Watanabe goes on to choose the one moment in which he showed love and kindness to his wife as his happiest memory, but the twist in the tail comes as his counselor, Mr Mochizuki (Arata) realizes that Watanabe’s wife was his own fiancée before he was killed in the war. Checking in the files on her choice of happiest memory when she passed through some years before, he finds that it was of him — by coincidence on the same park bench which Watanabe chose as the site of his happiest memory. At last he is able to choose because he finds himself part of somebody else’s memory. It is an even more elegant and moving way than Eternal Sunshine’s of making the point that, although our memories are also our selves, they cannot be merely private. It is the inclusion of other people through love that makes them happy.