My best teacher, without any question, was a larger-than-life, wonderful, potty, beak-nosed but rather handsome man, known universally as EJ - full name Ernest J Burton.
He was a defrocked priest who became the divinity master at The Latymer School in Edmonton, where I had my secondary education. From the age of 11 I would go to his classes and he would always choose me to read out passages from the Bible. I think he recognised the actress in me long before I recognised it in myself.
When I was about 12, our relationship took on a new significance. My mother had written to the school asking if I could have elocution lessons to rid me of the cockney accent that was the result of my working-class roots. We lived on the White Hart Lane estate in Tottenham and that was just how people spoke.
The English teacher volunteered for a fee that my family couldn't possibly afford. But then EJ approached me in the corridor and said: "You can come to me in the evenings and I'll get rid of that accent for you." So every night for an hour after school we would be like Henry Higgins and Eliza Doolittle. But I did lose the accent pretty quickly and have never spoken with it since.
What I didn't know at the time was that during our lessons other teachers would take it in turns to parade the corridor outside - in case there was any "funny business". Perhaps they detected a slightly unhealthy interest. But as far as I was concerned EJ was 32 - an old man - and besides, he never did anything to make me feel remotely threatened.
Certainly, however, there were odd elements to the relationship. He got cross with me when I started having boyfriends, for example. He directed many of the school plays and once, having cast me as Rosalind in As You Like It, he took the part away from me over some boy. He could be very difficult, which makes me wonder whether my attraction to tricksy men throughout my life began in some way with him.
The flip side was that he was completely fascinating. We would have long conversations in which I was forced to question absolutely everything I had been brought up to believe. It must have made me a nightmare at home.
But he opened my eyes and my mind and he even took me to my first play, King John at Regent's Park, although my mum came along too on that occasion, for propriety's sake.
It was he, too, who encouraged me to apply to the Guildhall, where I ended up winning the Shakespeare prize. Would I have gone there in the first place without his help, coming from my background and with my family's desperate lack of funds? I doubt it. But EJ showed me the way. So he gave me the wonderful life that I ended up having and for that I will always be grateful.
Perhaps to give credence to those who thought his motives weren't entirely pure, there was an even greater age gap between him and the girl he went on to marry than there had been between the two of us. Worse still, a Sunday newspaper ran a sleazy story about him building an altar in his basement where he would have sex with her.
I wrote to him to express sympathy and give him my support. He wrote back to say it had been a pack of lies, but his embarrassment meant that he never came to see me in the theatre. A shame, because no one deserved to be there more than he.
He died only a few years ago, living to a ripe old age. He had rediscovered religion and by the end was calling himself the Bishop of Kent or some such. Wonderful and potty to the last.
I wrote to him on several occasions to thank him for everything that he had done for me. Let the world say what it likes. To me he was simply the best teacher that ever existed.
Dame Eileen Atkins is appearing in `Doc Martin', which runs on ITV1 from 19 September. She was talking to Daphne Lockyer.