Instead, I went to the Marling School, in Stroud, a grammar school that suited me much better than Downside ever could have. Even before I left to go to Cambridge I knew how fortunate I had been to come under the influence of the Marling's teachers.
There were about 440 boys, drawn from an extraordinary mix of backgrounds. We were not lavishly provided for, but what mattered more was the human capital: the staff. I was there from 1959 to 1965, when the early beneficiaries of the 1944 Education Act were coming back into the system as teachers. Eric Pankhurst, who taught me history, had been the first boy from his grammar school in the Potteries to go to Oxford on what you might call the "'44 deal".
He and the others had a sense of mid-20th century possibility. In terms of social gardening, we were in an exquisite flowerbed, watered by men who treated us as intellectual equals.
If ever someone lived up to the image of the tremendously enthusiastic, curious, curio-collecting history master, it was Eric. He was very funny and boyishly excited by his subject - his enthusiasm for the thrill of the historical chase was contagious. Eric showed me the importance of having "bubble" in the classroom, and I hope my own teaching displays an element of that quality.
I'd like to have the organisational skills of Peter Young, my geography master. I remember Peter taking us on brilliant trips to the Black Mountains. Years after I had left, Peter became headmaster of the Marling.
By comparison, Cyril Campbell, my English teacher, was very disorganised. He was always late handing back our essays, but gave tremendous insight into the literature, and us.
I have never forgotten what he said after our mock A-levels. One of my classmates, whom I liked very much, always worked harder than me at his essays, but I would get better grades, despite English being the least of my three A-level "passions".
"Terrible shame about old x," Cyril said after the mocks. "He goes into the exam room with all the carefully acquired ingredients needed for a gourmet meal, cooks it, and the result is an absolute mess. You go in with the equivalent of a tin of baked beans, one egg and a couple of rashers of bacon and produce something utterly appetising." He said it with regret, and was basically letting me know that I was a lucky bastard.
I think of that trio as the Marling's engine room. They were also good friends and we all picked up on the fact that so many of the staff got on with one another. They all had an immense respect for learning - they wanted you to demonstrate your intelligence. Teaching was more than just a job for them.
The final member of the quartet who looked after me in the sixth form was Michael Gray. He taught French and was my form master. He was a mentor and had a shrewd insight into the potential, as well as the pitfalls, of late adolescence. I remember going through a very bad patch in the fourth form and having a very good conversation with him that forced me to grow up.
I felt tremendously proud on the two occasions that I have been invited to give the speech day prizes. I dedicated Never Again, my history of Britain 1945-51, to my teachers for having such an influence on my own history.
Peter Hennessy, 51, is professor of contemporary history at Queen Mary and Westfield College, London. His new book, 'The Prime Minister', will be published by Harper Collins in 1999. Peter Hennessy was talking to Daniel Rosenthal