One of the most important moments of my life was the first five minutes of the first rugby game I ever played at Harrow School. I thought I was a jack of all sporting trades - alas, within those five minutes it became obvious that I was never going to get on to any team. My entire view of myself changed. That’s where James Morwood came in.

James was a Classics teacher. But, crucially, he was also the editor of The Harrovian: the weekly school magazine. I thought I was going to be playing rugby, but I found myself getting involved in the magazine instead. It’s not an exaggeration to say that the start of everything I do now was thanks to James.

Every Monday we would have long editorial meetings where I learned all the skills that made me a sketch writer. I did reviews, comment pieces and funny articles where I’d try to conjure something out of nothing. I’d write “The 10 stupidest words we use at school” or I’d file a review of the school play in the style of T S Eliot. James was immensely encouraging. He was very particular and pedantic, very quality-driven but fundamentally impish.

I remember starting to write a weekly soap opera for the magazine. In the very first instalment a boy fell out of a window and was killed on the spikes of the railing below. James thought it was excellent, but the headmaster was less forthcoming. It never went to press. And that is why I’m a comedy writer and not the author of dodgy thrillers.

Near my final term, James had the idea that I would direct a play in Speech Room, the big school hall. I think I was the first boy to do so. I chose The Erpingham Camp by Joe Orton - an immensely satirical play - and the fact that James gave me the green light to do it was, essentially, him letting me know that it was all right to push boundaries and to be funny.

People used to think that if you were serious and scholastic - which I was - then you couldn’t be funny as well. James was absolutely key in helping me to square that circle. There were plenty of boring Henry James plays we could have done, or a miserable Harold Pinter, but James was thrilled that I came back with The Erpingham Camp, which was pretty much the most anarchic play one could find. He gave me that freedom and pushed me to do it.

I put a lot of stock in what students do outside the classroom. When I look at my son now, I’m more interested in the fact that he’s doing improvised comedy than studying physics, maths and English. I have a feeling that it’s the improvised comedy bit that will be his life. Perhaps the most important decision students make is their choice of extracurricular activities.

The school played a huge part in forming who I am. It was very hierarchical, old-fashioned, drenched in rules and traditions. I was happy there but I didn’t like the inequality. I didn’t approve of fagging [younger pupils doing chores for older ones] and at 18, when I became head of my house, I banned it. I didn’t like the authoritarian spirit at all.

I remember finding out how much money was donated during the church collection - mostly it was halfpennies, pennies or buttons. I made a speech in church, asking: “Are you really saying, when this collection that helps people’s lives comes around, you want to put in a button? You spend a quid in the tuck store and you’re willing to part with a button for the starving?”

And to this day, I hopefully do my bit. I’m working with the United Nations on the World’s Largest Lesson, which is all about injustice and inequality. It’s not as though I’ve experienced any of that myself; I’ve had the most lucky life. But my instincts towards inequality were really ignited at Harrow. The school, and James, did untold amounts to develop who I am and what I do.

Richard Curtis was speaking to Tom Cullen. He is leading Project Everyone, an initiative to communicate the UN Sustainable Development Goals to 7 billion people in seven days in September 2015. Find out about its lesson plan competition and take part in the World’s Largest Lesson at www.tesconnect.comworldslargestlesson

Rewriting the script

Richard Curtis

Born 8 November 1956, Wellington, New Zealand

Education Harrow School, North London

Career Comedy screenwriter and film-maker known for films such as Four Weddings and a Funeral, Bridget Jones’s Diary, Notting Hill and Love Actually, and sitcoms including Blackadder, Mr Bean and The Vicar of Dibley; co-founder of Comic Relief; awarded a Bafta fellowship in 2007