My father believed that if you paid tax you should use the services provided by the state, but he changed his mind when my older brother became totally unruly at 11, and sent us to private school.

My best teacher was the headmaster, Tim Paton, but I only got to know him well in the final year when I was 13. There was a unique character at St Anthony’s School in Hampstead which was created by Tim. All the teachers wore jeans and allowed us to call them by their first names. They had a very casual attitude as if they were preparing us for future life as young adults rather than kids.

It was 1977 when I moved into what was called the sixth form and Tim started taking us for English. It wasn’t really like anything that resembled a traditional English lesson. It was just an excuse for us to sit in his messy study on overstuffed chairs, listen to his stereo and discuss life.

On one occasion, he asked all of us - 10 boys - to lie on the floor and then he put on a Pink Floyd track and told us to: “Just get into the music man. ”

Other times he talked to us about everything from how we might get introduced to drugs in the future to sexual relationships. He didn’t talk about sex crudely - more about relationships with women, how to treat them and the differences between women and men. He was totally off the wall and we loved it.

Tim was a very big Irishman with shoulder-length red hair and a beard which made him look wild. He identified with everything that was important to us but talked to us the way he would have talked to adults.

We developed respect for him out of the way he showed respect for us. Everyone in the class was included in his discussions and he tried hard to bring us out of ourselves and talk to us in a way our parents would never dream of doing. If anyone misbehaved he would scream and shout. He didn’t ever hit anyone but if you did anything wrong he would shout so loud it was terrifying.

He used to teach our drama lessons too and was very interested in mime. There was nothing conventional about these drama classes and we never had to perform Joseph and his Amazing Technicolour Dreamcoat. Instead, we had to do unusual improvisations - impressions of National Front supporters or any topical characters of the time.

He used to get us all made up and then take us out on the street to perform in Hampstead. It was a totally revolutionary approach but I had no idea how unique he was until much later.

Tim made me become far more mature at a younger age. The confidence I now have in myself is down to the solid foundation that was laid by him at St Anthony’s.

When I left there, I was a rounded, young adult and not a 13-year-old kid. I was able to communicate with adults rather than kids and was attracted to friends who were much older.

The problem with St Anthony’s was that it was difficult to know where to go next, and that was the beginning of my chequered past. Tim wanted us to go to University College School because he felt it continued his methods but I wasn’t academic and didn’t get a place. Instead I ended up at Merchant Taylors where I didn’t settle very well.

There I was treated as a kid by the spotty prefects and was constantly getting into fights. I left at 16 with few qualifications and went from school to school.

I went back to visit Tim plenty of times after I left and, although I’m not in touch with him now, I still hold fond memories of him. A surprisingly large number of entrepreneurs emerged from Tim’s class. Matthew Freud who runs his own public relations company and Jamie Mars who has built up a restaurant chain, to name but two.

My time with Tim at St Anthony’s was an important stage of my life and I’m sure it was the confidence and maturity that he inspired in me at 13 that allowed me to start my first company at 21.

Dan Wagner is chief executive of MAID, (Market Analysis and Information Database) which he started in 1985. It is an on-line supplier of business intelligence services, including market research reports, up-to-date stock market and commodity prices