What he did for me - as he did indeed for many of my contemporaries - was to open my eyes to a whole world of contemporary culture. He took us off to the cinema in London to see Les Enfants du Paradis and used French lessons as a vehicle for introducing us to English poetry. He'd read, say, the 16th-century French poet Ronsard's famous sonnet and then study W B Yeats's English version. He encouraged us to read contemporary fiction and would ask if we had seen the latest Graham Greene. He was a friend of Henry Moore, and was himself a minor poet and very much a literary figure of the 1940s and 50s. He translated French to English and English to French and was much admired in France where he was awarded some national honour.
He wasn't particularly flamboyant. Most of the men in the common room wore sports jackets with leather patches on the elbows, but he was different. I remember he wore a widely-knotted tie.
There was a syllabus of books we had to cover to pass an exam, but he had no difficulty in finding the odd moment to widen our horizons at the same time. He tried to interest us in modern art and encouraged us to develop calligraphy. Even now, I still write in a rather sub-italic script.
Our attention was held, partly by the fact that he would branch off the topic and talk about other things but also because he took us rather Philistine, games-oriented boys behaving badly and showed us that there was, not only out there, but also within us, an appreciation of a different world. I certainly owe to him a blossoming of interest in literature, art, film, calligraphy - you name it. It doesn't make me an expert in any of them, but I hate to think how narrow or undeveloped my life would have been without him.
Walter Strachan came from Giggleswick in Yorkshire and had read modern languages at St Catherine's, Cambridge. He was a housemaster, but that wasn't his scene. His great contribution was to give schoolboys an opportunity to make contact with a creative world we might never have known.
I kept in touch with him after I left the school. Even after he retired he was still writing and giving lectures in France. He was a beacon of culture and I was very fortunate to have him as a teacher.
Lower down the school, especially when I was about 14, I was part of a group of boys who enjoyed breaking the rules. We tormented two teachers - I think their names were Herr Plaut and Herr Berger - both Germans who had escaped to England during the war.
Herr Plaut taught mathematics and was so short-sighted he couldn't see who was playing him up at the back of the class. He gained our respect in the end because, against colossal odds, he stuck to it and got us through our exams. Herr Berger, who I think taught French, was far too nice. He gave up in the sense that those who were naughty (and I was in this group) sat at the back and played cards or whatever, while those who wanted to learn sat at the front.
It is amazing that the headmaster, Arthur Evans, didn't know what was going on. He was a nice chap but not very effective. He was kind to me and gave me endless chances, probably far too many. My father, whom he sent for from time to time, took a fairly pragmatic view, but warned me: "I wouldn't push the headmaster too far if I were you."
We didn't steal, didn't do drugs because there weren't any, but probably were bullies in the sense that I think boys kept out of our way. We were very physical and had a lot of energy to burn. In these rather solemn days in which we live, we need to remember that parents then thought it was rather a good thing if in adolescence you kicked over the traces.
When I became a teacher - and eventually a headmaster - I felt a sneaking affection for rogues, having been one myself. I didn't take adolescent moods and peccadilloes too seriously. But headmasters have to be perceived as being firm. You can't be seen to be too nice because one of the points of adolescence is to kick against the bricks. A sense of humour is crucial,too. Most of the naughtiness of young people is part of normal growing up.You deal with it firmly because they need to know where the borders are, but on reflection it can also be very funny. Poachers turned game keepers could explain quite a lot of heads of school, let alone headmasters.
Dr John Rae, head of Westminster School from 1970-1986, is the author of 'Letters to Parents: how to get the best available education for your child', recently published by HarperCollins. He was talking to Pamela Coleman.