I didn't go to school at all for the first ten years of my life because I was ill almost all of the time. My mother was a brilliant teacher. She was one of those who could mug up on any subject and get people through an exam. In those days if you married you had to leave the profession, so she only taught privately. At home, education was regarded above everything else.
I was something of an oddity because I got no marks in my maths paper and 100 per cent in my English paper for the grammar school entrance exams - but they gave me a scholarship. Like all the other pupils, Welsh was my first language and although all our books were in English and we had to write our essays in English, the staff often taught in Welsh, and we slipped easily between the two languages.
Miss Inkin, a middle-class Englishwoman who didn't speak Welsh, was a curiosity in this environment. Most of the teachers lived in nearby villages but her home was some distance from the school and I didn't know much about her private life. She spoke French, and was very sophisticated and refined. She became great friends with my mother, as were most of my teachers. After I left she married Brinley Rees, a gifted Welsh scholar, and we were invited to the wedding.
I worked as a child actress with the BBC and performed in many private concerts. Miss Inkin took me under her wing and changed my wardrobe. This was the age of curly perms, high-heeled shoes and tailored suits but Miss Inkin had a straight Vidal Sassoon-style haircut and always wore exquisite flat shoes and wonderful clothes. Under her influence I dressed in black ballet pumps for my concert appearances, wore my hair straight, and instead of pretty floral frocks, wore a plain navy dress which had six widths of material in the skirt, a tight waistband and white silk collar and cuffs.
I was incredibly busy. As well as working for the BBC and doing concerts, I stayed behind at school every evening for choir practice, dance practice and action song practice to compete in Eisteddfodau and trained for exhibition gymnastics. We also had a lot of homework. My mother insisted I stayed in the top three of the A-stream or the acting would have to stop. The staff knew the deal and helped me. Several teachers gave me private coaching during the lunch hour to make up for time I'd missed, and there was no question of payment.
It was a co-educational grammar school but the sexes weren't allowed to fraternise. Boys and girls were divided within the classroom and the playground, and had separate entrances to the school. There were three streams in each year, with about 37 to a class. The staff lavished us with care and attention and put in a phenomenal amount of work on preparation and follow-up.
Homework was meticulously marked and there was always a post mortem. Even in a class of 37 we all had a great deal of individual attention.
I had several other "best teachers" apart from Miss Inkin. My Latin teacher, Miss Daniels, who was very shy and rather dry, was wonderful too. She taught me for six years and I loved every lesson. Learning Latin saved me from having to look up words, I could guess what they meant.
Another of my favourites was Miss Vivien Williams, who taught French. She was very glamorous and wore make-up, which was unusual then. Her clothes were always up to the minute and her hair beautifully styled. I loved French and spoke it quite fluently before I went to England and spoke English.
Miss Agnes Thomas, who taught biology and botany, was the pivot of my social life because she ran the Welsh youth movement, Urdd. She also gave me a love of botany which I still have. All my teachers gave me an enthusiasm for learning because they had a love of their subject. They became like family. I kept in touch with them after I left.
I wanted to go to the Royal Academy of Dramatic Arts, but my mother insisted I did a degree first. So I went to the University of Wales in Cardiff and wound up doing philosophy. It turned out to be a blessing - the university was just across the road from the studios, so I was able to have a proper job with the BBC and study for a degree at the same time. My mother always hoped I'd go off the idea of being an actress and become a teacher.
Sian Phillips plays Marlene Dietrich in Marlene, which opened at the Lyric Theatre, London, earlier this month. The only child of a teacher and a policeman, she was born near Pontardawe in South Wales and now lives in London. She has two daughters from her marriage to the actor Peter O'Toole, from whom she is divorced