Oh my, school was such a long time ago. And actually, at school I didn’t have a favourite teacher, there wasn’t anyone who had a huge impact on me. Then, aged 16, I went to art school and I met Philip Fortin.

Mr Fortin, or Piff as we called him, wasn’t very nice or even likeable, but he made an impact. He had a huge influence on me, but the way he went about it was a bit strange. He was a short little man; if you think of an art teacher, he absolutely fits the bill. He had a lot of iron-grey hair, a little goatee beard and wore tweeds with leather elbows in his jackets in all tasteful colours. He smoked this pipe, which was disgusting. You’d imagine he would have a gruff voice, but actually, he had a very surprisingly high voice.

He taught painting and from the moment we got into the studio to the time we left, he talked. He would wander in and out of the easels being horrible to us: he’d say we were no good and ask: “What on Earth do you think you’re doing there?” Teaching art in those days was very different to teaching it now - it was all very technical. There was none of this “don’t worry, just express yourself”! Piff was interested in spatial awareness, floor planes and surfaces, and would say: “Helen, why is that person floating three feet above the surface? What do you think you’re doing? Hopeless!”

We didn’t mind because he was the same with everyone - he was very democratic with his insults. In all the lessons he would go on and on and on: do this, do that, what do you think about this? He would only stop to refill his ghastly pipe before going again.

But, my goodness, you just remembered what he said. Technically, Piff was brilliant; you’d leave the classroom absolutely exhausted. What was extraordinary about him was that we didn’t have a clue about his private life. I don’t know if he was married or if he had children; I don’t know where he lived or even if he painted at all. It was very, very strange. He never really let you wonder about him because he was just on at you the whole time.

For years afterwards, whenever I was doing any drawing, I could hear him over my shoulder going on and on, saying: “Helen, that is not a floor plane!” So although he was not a very likeable person, he was a pretty good teacher.

I forgot everyone else; I never forgot about Piff. He knocked us down at every possible moment he could, and told us that we were wrong and that none of us would make it. Yet, we weren’t upset about it.

It’s almost 60 years ago and I still wonder, what was his life outside of the classroom like? But of course, it’s too late to find out now.

Helen Oxenbury is speaking at the Cheltenham Literature Festival on 13 October about her biography, Helen Oxenbury: A Life in Illustration

Born: Ipswich, 1938

Education: Ipswich School of Art, Central School of Art and Design

Career: Helen Oxenbury is an English illustrator and writer of children’s picture books. Her illustrated works include We’re Going on a Bear Hunt, Alice’s Adventures in Wonderland and The Three Little Wolfs and the Big Bad Pig.