Jonathan Holloway taught me A-level drama at Brooklands Technical College in Weybridge, Surrey, and he was completely different to any other teacher I had ever come across before.
Before Brooklands, I had been to a mightily expensive public school, but left when I was 16 with one O-level in English literature. The only reason I passed that was because the teacher said that it was the O-level I would perform worst in, so I had to prove him wrong.
I spent the next two years working as a porter at Yeovil District Hospital. What my parents must have thought, having lavished all that money on my education, I don't know. It wasn't the school's fault - I just wasn't motivated. But I can't have been stupid because while I was working as a porter, I re-took my O-levels at night school and passed them all.
Then my father, who had separated from my mother when I was very young, suggested that I go and live with him in Weybridge and take A-levels at Brooklands.
My initial reasons for choosing A-level drama weren't particularly noble. I hadn't done any acting before, although my mother was a leading light in the local amateur dramatics society and sometimes I went to rehearsals with her when she couldn't get a babysitter. But I was struggling to find a third subject to study so I was told to have a look around the college and see what I fancied doing. I wandered around and, right at the edge of the campus, I discovered a hut with a corrugated iron roof, separate from the rest of the college, which I later found out was referred to as the drama studio. I looked through the window and when I saw something like 15 girls and only six boys I decided that was the place for me.
Jonathan was very cool. It was about 1984 and he was a self-confessed Marxist and had that Eighties radical look - he used to wear patent leather Dr Martens, rolled-up jeans, denim shirts and he had quiffed hair. What made him special was that he was passionate about his subject. He was very proactive - drama is all about working as an ensemble, rather than sitting there having facts droned at you, which is what I had been used to.
Right from the start he challenged and provoked us. We were a bunch of privileged kids from Weybridge who, by and large, had come from pretty well-off backgrounds and whose previous knowledge of theatre probably extended no further than Cats and Evita.
Jonathan introduced us to some very complex ideas about drama - my stage debut was in Brecht's The Resistible Rise of Arturo Ui, which we brought to the Edinburgh Fringe. He also introduced us to Augusto Boal, a Brazilian theatre director who founded the Theatre of the Oppressed. It was a real eye-opener.
He made anything seem possible. It was Jonathan who suggested I might become an actor. He instilled in all of us an attitude of complete professionalism, regardless of whether we were being paid or not.
I haven't seen him for a couple of years as we are both so incredibly busy, but I'm sure we will always be in touch. He certainly changed my life.
Actor James Purefoy, 47, has appeared on stage and screen, most recently in 'Rome' and 'Ironclad'. He will be starring in 'Injustice' on ITV1 at 9pm from 6 June and then every night that week. He was talking to Hilary Whitney.