The summer I left school, I looked much the same as when I started there, seven years previously. I still wore white ankle socks, Clark's sandals, a hideous tie of navy-and-gold stripes and an even more hideous beret with a gold badge on the front. Girls have ways with berets now and the art of customising a school uniform comes easily to an 18-year-old. Then, the year before the confident Sixties began, there didn't seem to be ways with anything.

I left school with relief, had a ceremonial burning of the beret in our garden and almost immediately left for Norway, where a family friend had arranged an exchange with a Norwegian girl, Anne-Grethe Holm.

There had never been such freedom in my life as was represented by this three-month break before university in the autumn. The young now sensibly award themselves years off as though this were written into the educational curriculum: a year off between school and university; another between university and a job. I wish we had thought of that.

For me, Norway represented what India and Thailand became for subsequent waves of school- leavers. Not that it was on anybody's must-visit itinerary, but it symbolised escape from the known. I had never slept at sea before, as I did on the crossing from Newcastle to Bergen. I had never been in a place where I could not understand a word of what was being said to me. In fact, I had been abroad only once before and that was to France.

The summer of 1959 was remarkable for its heat. There have been heatwaves since, but that one was the first that made any impression. The heat somehow was an integral part of the transmutation of that summer.

In Norway, I shed the ankle socks and padded about barefoot like the rest of the tribe of young people whose families summered on the fiord. Hardly front-page news, I know, but it was the beginning of a whole process of reinventing myself: the way I looked, the way people thought of me. Of course, there wasn't any grand plan. It wasn't even a conscious process, but cut off from everything I knew (a phone call home would have been an unthinkable extravagance), I became vividly aware that there were new and different ways of doing things.

The Holm family's wooden summer house was built by the side of a fiord, just outside Sandefjord. Their winter home was in the town, where Anne-Grethe's father disappeared to work every day. Below the summer house were rocks and a jetty; behind were woods of pine and birch. Perhaps half-a-dozen times that summer we went by car on an expedition; the rest of the time we spent on or in the water.

Having grown up deeply under the influence of Swallows and Amazons, I could swim, row and handle a sailing-boat reasonably well. The new and wildly liberating angle to this in Norway was that it all happened without a grown-up in sight. No one shouted instructions about the best way to come alongside the jetty. No one told you what time you had to be in at night.

There must have been about 20 of us, all about the same age, knocking around in that summer's gang: 19 Norwegians and me. The fathers went off to Sandefjord each day; the mothers did I never discovered what; and we picnicked, sailed, fished, swam, made barbecues (my first), and every night partied at a different person's house - rowing or sailing ourselves home by the light of the moon at two or three o'clock in the morning. Elvis Presley provided the only common ground.

When you are crashing about as we were, it does not matter that you cannot converse deeply and meaningfully with your peers. You still communicate. You still pick up the undertow of what is going on in the group. I learnt enough Norwegian to survive. The gang had enough English between them to fill in the gaps.

Some days we rowed with a picnic lunch to Longholm, a biggish island in the fiord, and swam and sunbathed until it got dark. Some evenings we would sit on the jetty with mussels tied to long pieces of string, fishing for crabs. The trick was to flip the line on to the jetty before the crab let go of the mussel. Then we tossed the crabs into a cauldron on the bonfire and ate them for supper.

We raced dinghies across the fiord, playing a slightly nerve- racking game of who dared be last to avoid the vertical rock face that fell down there into the water. We went to Seilholm for the regatta and sailed much bigger boats on a course that took us out of the fiord into the open sea.

We swam with Coca-Cola bottles on our heads (no one drank alcohol) out to an uninhabited scrap of island, sand and heather, where one of the boys - Petter? Roar? Turen? - taught me to rumba while the others beat out the rhythm with stones on the rocks. For heaven's sake] The rumba] On an uninhabited island] With a gang of people straight out of Ingmar Bergman's Summer with Monika] How liberated could you get in 1959?

I learnt a lot from that gang. Mostly how to operate in one. It was the first holiday I had ever spent with a large, mixed group of people my own age. All holidays except the one in France had been with my parents. And in Norway I shed a lot of the muddling baggage that a single-sex education can leave you with: boys as Martians, to whom you speak and behave in a different way from your own sex. There were no couples in this group. All dressed in much the same way. I got my first pair of unisex jeans in Norway. Until then, like most girls in England, I had worn trousers that zipped up at the side. My front-buttoning pair were a sensation when I returned home.

I have learnt since that I am only really happy on holiday in places where there are mountains. I didn't know that then, but they were there anyway. Even in Oslo, where I went at the end of the summer to stay with Anne-Grethe's cousin, Ellen, you could cycle easily from the centre of the capital out into the forest and mountains. It seemed eminently sensible that freedom and solitude (though I wasn't much into solitude at that time) should be within easy reach of all the people in the city.

We went to gaze at Edvard Munch's paintings, troubling even then, though I couldn't have said why. We went to admire the Viking ships. We walked frequently in the Frognerpark among Gustav Vigeland's monumental carvings. I heard the music of West Side Story for the first time in an Oslo flat. Finally I left for England by way of the Fred Olsen Line. Some of the gang came to Oslo to see me off, with bunches of carnations and roses that filled the handbasin of my cabin.

On the way out, I had spent much of the journey in my cabin, not knowing where I was supposed to go to find food, scared that someone might try to strike up a conversation. I scarcely saw my cabin on the way back. Within an hour I had fallen for a lanky, fair- haired, green-eyed Norwegian boy called Tore. We played cards, liar dice, drank Tom Collins (my first gin), and stayed up all night dancing to a gramophone in the saloon. The barman thought I was Norwegian, too. We never told him the truth. There's neither time nor the opportunity to fall in love on an aeroplane, but boats are good for romance.

Part of the romance was to bring the thing to an end at Newcastle. Affairs rarely have such neat conclusions. I hated seeing England again: drab Newcastle, filthy train, grey weather. I cried all the way to Birmingham, where my parents had arranged to meet me.

I stood on the platform with my huge suitcase, watching my father and mother working their way towards me. I smiled, stepped forward - and they walked straight past me.

'But your hair]' said my mother later, trying to explain why she had failed to recognise her only daughter. 'It's gone so fair]' That was true. After a lifetime of mousy brownness, my hair was bleached clear blond by a summer of sea and sun. 'And you are so brown]'

That was true, too; but the real change, the reason they did not know me on the platform of Birmingham New Street, was much more complex. In Norway I had shut the lid on childhood and started the business of being grown-up.

(Photographs omitted)