WHEN I was six, the age my youngest son is now, my father took me and my older brother to see a film of the highlights of the Tokyo Olympics of 1964.
In those days, RTE television coverage of the Olympics amounted to a few father badly shots black and white images. People still went to the cinema a few months later to see the best bits in colour, to make it all both more real and more, glamorous.
From all the succession of sporting heroes parading across the screen, just three images were impressive enough to stay with me. One was a huge Russian weight lifter teetering for a split second with the weight above his head, before his knees buckled and his world fell in. Another is an African runner who ran, and won, in his bare feet.
And the third was not an individual athlete but a race - the marathon. My memory provides no specifics. I have no idea who won and in what time, whether the race was close or whether he won by a mile.
What I remember is that there was a huge crowd on the streets of Tokyo to watch the runners and that, like them, I felt an overwhelming, sense of awe at the very notion of running so many miles. Here was the impossible made real, wonder in a sweaty vest.
On Monday, I'm going to run the Dublin City Marathon myself. I set down that sentence quickly so that it will be fixed in print and become an inescapable fact, a sentence from which there is no appeal. But it isn't, after all, a big deal. The way we live now is to make the marvellous mundane, to transform the heroic into the everyday.
Every year, thousands of ordinary people perform a feat that used to be the preserve of supermen. That they take twice or three times as long to do it hardly matters: the essence of the marathon is not time but distance.
This is, in itself, a fine thing, but it is also vaguely disappointing. Discovering that you, too, can run a marathon is a bit like discovering that there's no Santa Claus - another little bit of wonder goes out of the world. Although my heart is almost brimful of terror at the prospect, there is just enough room for a little bit of guilt.
Puffing gracelessly up the Swords Road, I have to face the fact that as a grotesque moving parody of athleticism, I am making a mockery of the Tokyo runners that I wondered at as a kid, betraying the pure awe I then felt.
IT IS, of course, a commonplace that running marathons is just one the things men do to convince themselves that they are not middle aged. (Why women run marathons is another matter altogether - popular wisdom is silent on the subject.) The glint of sweat on a spreading bald patch is generally taken to be a sure symptom of mid life crisis.
What all the knowing smirks I have been getting from my friends and neighbours these last few months suggest is that the desperate panting of the long distance runner is actually the pathetic last gasp of the macho man, that setting your stopwatch and stretching your achilles tendon is just a slightly subtler version of putting on a gold medallion and opening the top four buttons on your red lame shirt.
But the truth, I think, is somewhat different. The desire to run a marathon is, indeed, about the onset of middle age, but in a psychological rather a physical sense. It is about the death of childlike wonder and of the fantasies that beset those of us who were never any good at sports.
Seven stone weaklings tired of having sand kicked in their faces don't actually send away for Charles Atlas chest expanders. They take up running, an activity of which the essence is neither speed nor style, but the mere ability to carry on. They fall in love with long distance.
In my case, the need to run derives from a childhood during which I was subjected to a form of abuse called Gaelic football. This mostly involved being forced to wear a penitential hairshirt disguised as a football jersey while being kicked and pushed around a half acre of muck. I was a member of my school team, not because I was any good, but because I was too puny and timid to endure the special wrath reserved by the Christian Brothers for those who refused to turn up.
The main feature of my playing style was persistent failure to get out of the way quickly enough when a rain sodden leather ball was driven hard at my cold and naked thigh, producing multicoloured mottles on its delicate skin. Whenever the ball accidentally found its way into my hands, I would close my eyes and boot it blindly in any direction while a red faced Christian Brother on the sidelines roared: "Christ, O'Toole, you couldn't hit a cow's arse with a shovel." Such was the trauma that I have in later years occasionally, been found in the middle of the night sleepwalking towards a herd of Aberdeen Angus, shovel in hand, muttering: "Look, Brother, I can do it."
FOR a long time, John Aldridge stopped me from undergoing the obvious therapy of long distance running. The Tranmere striker is the same age as I am and so long as he was still playing for Ireland, I could still imagine lobbing the English goalie from the edge of the box in the World Cup final.
Then Aldo finally began to look clapped out and became a player manager. You know you are getting old, not when the policemen start to look young, but when there's no one your age playing serious football. There is nothing left for it but to embrace reality in the form of a pungent running shoe.
When you watch people playing football or tennis in the park, you can almost hear the television commentary inside their heads a breathless "He turns, he shoots, he scores" or a hushed "Championship point to Mrs Murphy."
Little kids now do slow motion replays after they have kicked the ball between the two piles of jerseys that mark the goal. But when you go running, you leave fantasy behind. You close your own front door, step on to a familiar footpath, skip past a familiar dog turd. You pass the neighbours, the old trees on the avenue, the bored faces in the stalled cars.
You traverse a quotidian world, free from the invasive presence of imaginary television cameras. And every twinge and ache reminds you that you are in, not some Olympian body beautiful, but your own accustomed bag of bones.
That, I suppose, is what middle age is about coming to terms with the way things are. Sometime around one o'clock on Monday, I hope to enter that state of grace, to shed in blisters and sweat a wonder that struck me when I was six. One of the pleasures of incipient middle age, after all, is the realisation that there is a lot to be said for mere endurance.
P.S. I am running the marathon in aid of the Rape Crisis Centre. All offers of sponsorship, however large, will be gratefully accepted.