Got that sinking feeling ...

One night, not long after my 40th birthday, Death visited me as I slept. "You are going to die," he told me, in a voice that sounded like my own. "You personally. Not someone else, not President Kennedy, not the victims of some road crash, not poor old Auntie Olive aged 91 - but you. It's already half over, this life of yours, and you're not having another."

One night, not long after my 40th birthday, Death visited me as I slept. "You are going to die," he told me, in a voice that sounded like my own. "You personally. Not someone else, not President Kennedy, not the victims of some road crash, not poor old Auntie Olive aged 91 - but you. It's already half over, this life of yours, and you're not having another."

I found myself suddenly awake, sitting bolt upright in bed, shouting "No!" at the top of my voice. Panic - that was what I felt. The panic of someone with an exam in an hour's time, three years' worth of undone work to make up, and no chance of getting through it before the Great Invigilator invited me to turn over my final paper.

So that was it, then. I would now never hitch-hike across America from California to New York. Nor would I become lead singer in a folk-rock band. I had left it too late to become prime minister. Most of the places I hadn't gone I would now never go; virtually all the things I had not become, I would never be. I wasn't young any more. Not in any way. I was too scared even to weep.

The next morning I realised that I was, of course, at the beginning of my mid-life crisis. And I could deal with this, essentially, in one of three ways.

The first strategy involved capitulating and meekly accepting that the interesting bit of my life was over. We would go on holiday to Crete or Cyprus every year, where Costas would reserve our usual rooms. At work I would eventually be kicked upstairs, become head of strategic evaluating and then get a good redundancy package at 49 years and 11 months. At home there would be ushered in two decades of baggy pullovers, elasticated slacks and gentle jibes about my ballooning figure. Maybe I'd take up golf and complaining.

Strategy two would be to make an old fool of myself. I would buy a motorbike, take flying lessons, have my nipples pierced, pull my hair back in a ponytail and stop eating. The Independent would be thrown away, and instead I'd scan men's magazines for clothes ideas. I'd start dressing myself in DKNY and Issey Miyake. In the office I would prowl the corridors looking for young women to make suggestive remarks to. I would finally get my leg over a youthful employee with whom I'd been having an e-mail dalliance, and then carry on a preposterous relationship which would end with my getting caught, shamed and possibly divorced. At which point I could revert to strategy one, or repeat strategy two for as long as my health and money held out.

And then there was strategy three: make the best of it. Every now and then you meet someone tanned and bright-eyed, laughter lines creasing their upper face, good white teeth, a fond wife and daughters, and they tell you that they're 67 and off to the Galway fiddle festival to meet up with old friends. And you think: that'll do for me.

But, to stand a chance of eventually becoming one of these gorgeous pensioners, my life had to change. Specifically, I had to do two things: first, get out of my terrible, mind-numbing job and, second, have an adventure. Within months I had accomplished the former. I had handed in my notice to general amazement, and departed. Did I feel better for it? Yes, I did. And the adventure? The adventure came a bit later.

On the last day of May 1998, at the age of 78, my father died. Despite a decade of various cancers, he'd managed to have a very good last 20 years: he'd dashed around Europe with his partner, Annie, driving hundreds of miles to see a beloved painting in a German art gallery, before heading for the Dolomites, where he would happily scramble across glaciers. Dad had managed to postpone his retirement until his mid-seventies and, till the last week, still worked a good 10 hours a day on the projects that interested him.

During the quiet, tearful period after his death, we took the kids off to Center Parcs to get away from sympathy and phonecalls. And it was there, as my five-year-old daughter and I were paddling a large green plastic canoe across the artificial boating lake, that a very good idea came into my head. I knew, at last, what my adventure would be. I would propel a kayak across England. Of course!

Using canals and rivers, I'd construct a journey that would take me through cities and countryside. The moment I had this idea, there was never really any doubt that I would actually do it. Why hadn't I thought of it before? Just for emphasis, I did an extra lap of the lake, overtaking a dinghy and shooting past a surprised pedalo.

As the week went on, I conducted a secret internal dialogue about this journey. After furtively consulting the atlas in the car, I could see a number of routes that would take me through places I wanted to visit and then back again, by water. These varied between 1,000 and 1,200 miles in length, depending upon diversions. But where was I going to stay? Everywhere and anywhere. At hotels, in small waterside inns, at isolated bed and breakfasts, wherever there were encounters with my fellow country-persons to be had.

No one, as far as I knew, had canoed across England. They were for ever walking across it, of course. From south to north, around the coast, up the middle, round the sides, in wheelchairs, on one leg, carrying heavy electrical goods, with no money, with a dog, with a horse, in the company of Ian Botham, each walk slightly more improbable than the last. Walking, though, usually meant sticking to tracks and paths, thus avoiding towns and conurbations, the places where things actually happen.

Water, I reasoned, was better. The rivers were England's first highways. All those tedious goods that the Phoenicians traded with the early Britons were carried into the interior by the waterways that nature had carved through the landscape. For the 1,300 years between the collapse of the Roman empire and the early stages of the Industrial Revolution, no effort was made to maintain England's roads. When Daniel Defoe rode the kingdom in the 1720s, the best highways were still those laid down by the legions over a millennium earlier; the rest was potholes and footpads. Water was the way to get about. The great castles commanded the heights above the rivers, and the fords across them. The Thames was navigable for 150 miles, the Severn for 150, and the Trent for 180.

In my little canoe I would paddle into the heart of Middle England away from the city, observe its customs and rhythms, and talk to the people in it. Then I'd come back and write the truth about it. I also hoped that I'd come back a better person.

This was a whole lot of agenda for one journey. Sort out your country, find yourself and paddle a thousand miles. It was, on any proper reflection, a silly thing to do. Quite unlike me.

So I went out and bought the maps.

If you want to know how the English lived on the cusp of the last millennium, then visit Milton Keynes. Hidden by trees, and announced only by their pantiled roofs, lurk little settlements of one- and two-storey houses, arranged around closes and avenues in arbitrary and irregular relationship to each other.

Like the small-holdings of Saxon villagers, each little house has a garden, where hanging baskets and rockeries take the place of chickens and cabbages. These settlements are mostly called "parks": Downhead Park, Giffard Park, Willen Park. There are no shops in them, no places of work, nothing but the houses themselves, separated by lawns and wooden fences.

The Grand Union canal enters Milton Keynes from the south, describes a great curve close to its centre, and departs to the west. For most of the 10 miles that the city and the waterway keep each other company, you would never guess that England's most notorious new metropolis is within cooee-ing distance. There are a few more bridges, every few minutes there is a glimpse of an estate of tiny semis, and - once or twice - a modern, pale brick public building: a sports hall, perhaps. You will not find a waterside cathedral, old wharves, an opera house, some grubby slums, or a tower topped with penthouses.

By the narrowboat marina near Peartree Bridge, a crescent of two-storey houses in brick and wood sweeps down to the waterside, each with a balcony overlooking the slate waters of the canal.

And that's where I made landfall. Two miles or so from Peartree is a windswept plateau where the strange heart of this city beats. In the early Seventies, before the long, glassy buildings appeared up here, some 40,000 people lived in the villages and small towns of this part of Buckinghamshire. Now there are a fifth of a million, and new plans were announced recently that will add another 80,000 people by 2010.

Milton Keynes horrifies some sections of the media; the young, ultra-sophisticated urbanites who like to eat in restaurants where syringes and bandages are part of the décor. They loathe MK. All they know about it is that once concrete cows stood in one of its meadows, and that children on bicycles with balloons were used to advertise its virtues in the Eighties.

Certainly, the main square by the station, a great, windswept, featureless expanse, is not easy to love. On the day in mid-June that I stood in it, I was the only human being there. Around the square stood 20 or so flagpoles, on which the only flags wagging in the wind were the red dragon of Wales, the cross of Norway, and the sepia company logo of a huge, ubiquitous finance, banking and insurance company. Arbitrariness, I was discovering, is a characteristic of English provincial life. From the square I walked down the boldly utilitarian main drag to a large, three-storeyed building in glass and gun-metal grey: Milton Keynes shopping centre, the first really great English mall. There are plenty of others now, but this one was the earliest attempt to provide in England what Californians and Floridians had been enjoying for decades. A modest entrance led me directly on to the ground floor of a large department store. Outside, there had been nothing; inside, there was everything.

There was the melodic hum of distant muzak, accompanied by the million small electronic burps and farts of mobile phones, pagers and cash registers. A foot away were 40 kinds of umbrella, from great golfing pagodas to flick-brollies that open savagely at the press of a thumb. A little bit further on, antiseptic-looking women - first cousins of air stewardesses - surrounded by crystal bottles and green liquids, sprayed perfumes at each other and grinned. Signs pointed towards food halls, menswear, cafeterias, electrical goods and exits to the rest of the shopping centre.

The department store gave on to a vast indoor hall, lined with two storeys of every kind of shop. These 50-foot high corridors were home to a straggling line of incredibly tall, etiolated cacti, beneath which the previously invisible people of Milton Keynes had magically materialised, as though teleported from their pantiled Parks, miles away. Here they all were, mums and teenagers, toddlers and grandpas, sitting on wooden benches, peering distractedly through windows, sipping cappuccinos in not quite alfresco cafés, strolling slowly, singly and in groups. Even the fire brigade and the girl guides had stalls here, and the cancer charities sold their flags. You could live here, and never want to go anywhere else.

An older friend of mine once lost his wife in Milton Keynes shopping mall. One day in the mid-Eighties, he came down with a terrible headache, and went home early. No wife. She eventually rolled in - just before the kids - at 3.30. She was surprised to see him. She'd had lunch with a girlfriend at the cafeteria in John Lewis's department store. The trouble was that my friend had been in the mall that weekend, and seen that the John Lewis cafeteria was closed for refurbishment for the next four weeks. And all of a sudden he knew, without a doubt, exactly what his wife had been having for lunch. He just didn't know whose.

How many other brief encounters, I wondered, had taken place in the five department stores, 20 clothes shops, dozen food places selling exotic breads and spices, dozens of weird sweet stalls laid out on ye olde golde-painted cartes, toyshops, mobile phone emporia, 15 bistros, two computer vendors, eight electrical goods outlets and seven shoe-sellers that made up just the North Hall?

But as I sat in the square, beneath the modern metal Anglos, the heretical thought suddenly came to me that this was all just fine. The food halls were full, not of ersatz rubbish, but of desirable breads, of organic honey, of home-made pasta sauce, of coffees and teas from all over the world. And most of the folk I saw here were happy. Despite the temptations and the occasional silly shop, they didn't creep around in a zombie-like state of shopaholism, of gift addiction. They gabbled and scrutinised and smiled and wheeled their kids to and fro, and met their lovers in John Lewis's cafeteria.

I took a taxi back to the marina. And as we drove I wondered: was it such a terrible thing to want to live in a place like this?

Extracted from ' Paddling to Jerusalem', published today by Fourth Estate (£16.99)