The Queen's School in Bushey had switched from being a grammar to a secondary modern in my second or third year, which meant that there were suddenly girls in class. There were seven girls and me in my A-level English set - which was just fine.
We were taught by Kenneth Hardacre, a small man who wore neat suits, glasses and good shoes. He had a little moustache. He was a theatre buff, to the extent that within the English syllabus he chose a few poems, a book of short stories and about a dozen plays. That wasn't so remarkable, as the syllabus allowed it.
What was remarkable was that we went to see every one of those plays, every damn one - which was pretty magnificent. We made lots of visits to the Aldwych Theatre for RSC productions, including Othello. I also remember Sean O'Casey's Juno and The Paycock at the Mermaid Theatre, and the Actors' Company in 'Tis Pity She's A Whore with Ian McKellen.
The highlight of that day was Mr Hardacre having a stand-up disagreement with McKellen in the post-show discussion. He got up and said how wonderful it was that the play's theme of fate driving people's lives had been so expertly shown to be true. McKellen replied: "It's a great shame you think that, as we were trying to do exactly the opposite and I think we achieved it." Sticking rigidly to his view, Mr Hardacre insisted: "No, you didn't." Magnificent.
His finest moment, however, came one Thursday morning when he was 45 minutes late for class. This was unheard of. We were quite concerned and I remember someone went to the school office, but they said: "We've had a call and he's on his way." What had happened was that he'd got up that morning, opened the Daily Telegraph and seen that Peter Brook's A Midsummer Night's Dream was coming to London to finish its world tour with 10 performances at the Aldwych at Christmas. He'd got on the Tube at Stanmore, gone into the West End, bought a dozen tickets and come back to school.
He came into the classroom like a gnome, glowing. "I have great news," he said, and fanned out the tickets on his desk. Seeing that show was hugely important - it was a seminal production and Mr Hardacre knew it.
The key to being in his class was that we all came to know that plays were there to be performed and watched, not studied as cold texts. There were a couple of B grades but the rest of us got As, as we were terribly articulate about the nature of the theatrical beast. We were a tiny, well-behaved class, very quiet, not a rebel among us.
The only thing I'd say against Mr Hardacre was that his idea of a classroom treat at Christmas was to let us help him do The Times crossword. I remember his glee when he got a clue right, even though we hadn't helped. That was very endearing, as was his hobby: printing. He used to print Christmas cards on his home press, and he'd bind up obscure Ted Hughes poems as Christmas gifts.
He was the most teacherly teacher in the school, by which I mean he wasn't anybody's mate. There were other, terribly valuable teachers who treated you like an adult and who would appear in the pub and almost buy you a drink.
Mr Hardacre wasn't dynamic. He was a short Mr Chips. I can't remember his style of teaching - what really mattered was his effort and his love for the subject. It was the first time in my life that someone else's effort had an important effect.
I was far too shy to act in school plays, and so my first route into theatre was through his lessons and those visits to productions. The shocking truth is that, very probably, I wouldn't have become a writer and director if Mr Hardacre hadn't chosen a dozen plays.
He and I had a reunion when my play Insignificance was staged in 1982. He came and watched, and spilt his wine with excitement in the interval. He loved the play and was just so pleased that one of his pupils had written it. I dedicated the published version to him, and I know he appreciated that. I knew at the time that it was a vaguely nice thing to do, but later on I realised just how much teachers deserve that kind of recognition - and one wonders how often they receive it.
He must have been 60-odd when he taught me in 1971-72, and I heard last year that he was in a home after a stroke. Another Queen's teacher wrote to me and said Mr Hardacre loved receiving letters. So I wrote him three or four pages of my news. I didn't expect to hear back, and I didn't. But I was confident the letter would be read to him. He died last year.
The opportunity to dedicate books and plays is a lovely thing for an author, and it should be used for those "people without whom this would not have been possible". After my parents, I think that applies most strongly to Mr Hardacre.
Terry Johnson, 43, playwright, has won two Olivier Awards forBest Comedy, for 'Hysteria' (1993) and 'Cleo, Camping, Emmanuelle and Dick' (1999). As a director, his productions include 'The London Cuckolds' and Philip Ridley's play for children, 'Sparkleshark', which runs at the Royal National Theatre until June 25. He was talking to Daniel Rosenthal.