We had pulled out of Paris as the sun went down over the palms of the Jardin des Plantes. The map at the end of the corridor helped us mark progress as each station loomed out of the darkness - Orleans, Chateauroux, Limoges, Brive and on to Cahors, famous, I was later to discover, for its medieval bridge and powerful red wine.
To us in that summer of l960, the world was young. John F Kennedy was about to be elected President. We were away from home and thought we were in love. Home was Wakefield in the West Riding of Yorkshire which had the good sense to have an exchange with the Department du Tarn in the warm south. The French students had already spent a fortnight with us. Now we were on their side of the English Channel.
Of course, they did not call it that. No way would the French acknowledge that any channel of water was actually English. So they called it "La Manche" - the sleeve, for that's what it looks like on the map. This was one of my first steps in unlearning my English certainties. There were many more such steps to take.
Of course, I knew people who had been to France. Curiously, though, they had only met Germans and then not on an intimate a basis. They had been primarily charged with shooting at them.
My uncle Arthur was on the Somme. He had driven trains much like ours up to the front in 1917, loaded with ammunition and thousands of tons of high explosive. He came back with a fiddle he had liberated from a German trench and talk of "san fairy anne" and a lady from Armenti res.
The smell of fresh bread plunged me into my France. It was before 7am when we had been tipped out of the clanking local train from Toulouse at the station in Castres. Yet the baker's shop was open and doing good business. We tore off chunks from the baguette to keep us going till breakfast. My first real culture shock.
They put butter and jam on this wonderful bread and then dipped it in a huge bowl of coffee as black as the night just gone. It was a crucial test. It ranked with Suez as part of my social and political awakening. The hoary old certainties of Britain's imperial past spun by Gaumont British News were reeling. Breakfast didn't have to be a cup of my mother's Yorkshire tea.
The next three weeks were a whirl of sights and sounds, tastes and smells; string beans cooked in olive oil and garlic, miners shouting "joli" at the opening rugby league game of the season at Carmaux, fields of lavender in bloom, sand and the Mediterranean sea between my toes at Collioure where Impressionists had set up their easels, and the noise of the crickets that kept me awake at night.
The town hall had formal gardens by Le Notre, who went on to design those at Versailles. What would they make of the Age of Reason back on the allotments in Wakefield? I know what they would have done with the bloody beef. But I did not care when the sun beat down on my back as we sailed on the Bassin de St. Ferreol, played table football in the cyclists' bar under a cloud of Gauloise smoke and danced through the night.
Racine and the past pluperfect had not prepared me for this: girls called Genevieve and Chantel with dark eyes and bronzed skin, careering round on a moped on the "wrong" side of the road, a grandmother whose first language was Catalan, the stench of open sewers in the back streets, red wine that would dissolve those Vichy alloy coins, elegant married women shaking my hand and calling me "jeune homme", and the sudden violence which flared as we were confronted by fearful, drunken conscripts en route to the Algerian War.
"Why did you abandon us at Dunkirk?" asked an old man. Or more difficult: "Why did you bomb our fleet at Toulon?" Then from a French lad the insistence that BP petrol and the board game Monopoly were French. They hammered us at petanque to establish superiority. I was too busy watching their body language to be riled.
In truth my exchange student was dull. But I loved his dad, with his impenetrable, nasal Midi twang, his dirty jokes which I didn't understand and his genuine desire to communicate. His mother too, who was only too pleased to show me how she prepared cassoulet toulousian and gigot a la provencale to fill those two-hour lunch breaks.
In retrospect, my French exchange taught me more about being English than about France. It set me on a trail of unlearning my prejudices. Under the shade of the plane trees I read Camus's L'Etranger, housing as it does a heady brew of ideas, sunshine and violence, quite alien to Britishness. It was not just my skin which betrayed my paleur anglaise.
I love France but not in some dilettante sort of way. Of course their wine, their food, and their style are to be admired. But their idiot concepts of glory, their desire to gun down every small bird that takes to the wing and their insularity are only of use to us when faced with a "compare and contrast" essay on our own foibles. And how dare Napoleon call us a nation of shopkeepers?
Their attitude to sex seemed more enlightened at first. Yet the paintings of prostitutes by Toulouse Lautrec in his home town museum at Albi demonstrated something darker. In l960 daughters were still firmly under lock and key and wives tied to the stove.
I was shocked by the rigidity of the class system too. My French family were in trade, albeit wholesale. My girlfriend's host was a lawyer. I called on her one evening after dinner without prior invitation. It was made plain to me that I had unwittingly crashed through an unseen social barrier.
As we toasted our farewells in the sparkling wine of nearby Caillac, I knew something in me had changed irrevocably. I had passed through a door. The certainties of nationality now appeared something imposed on me by newspapers, politicians and insecure fellow countrymen. They did not define nor confine me. I had learned to talk to people in their own language and to try to make sense of what they said and did.
I thank those teachers who opened up France to me. It gave me the confidence, after school, to study German and make sense of that country and its people too. A process which involved unlearning the crude simplicities of 100 war movies. I also thank others that I, and the many thousands of exchange students since, have never had to hit the French beaches under hostile fire.
But the xenophobes are still with us. No matter how many Costa holidays pupils take, there will always be a need for genuine exchanges of our sons and daughters, of our customs and our ideas. The most famous of those Goya prints warns of the consequences of a neglect of understanding: "the sleep of reason brings forth monsters".
Chris Johnson lives in Newcastle upon Tyne