I say more or less because, for the past couple of years, I’ve done other things. I’d reached a point in my career where I was no longer the young, trendy, patient Sir full of inspired ideas and hours of extracurricular time, and was devoting more and more time to discipline and “achievement” issues. The fun was going out of it.

So over the past two years I’ve read about 100 books, moved around a bit, taken a few chances and thought a lot about who I am, where I’m going and what I want. It’s not all been good. A spell on the dole made me long for a job, and a wild social life takes its toll when middle age looms. Last week I went for an interview and got the post.

The most remarkable thing about the interview was the lack of anxiety. I decided to try to put across the person I am, rather than showing what I know. I wasn’t expecting the job or depending on it.

When the euphoria had worn off, mild panic set it. How would I cope with the name-learning, rope learning, office politics and being in role again? How would I manage stress and juggle all that paperwork? Would technology defeat me? But it’ll be OK.

Taking a break has allowed me to rediscover my vocation. I’ve revisited my original ideals and am remembering the things I love about teaching: witty comments and jokes in the staffroom; excited whispers from students; and the daily minor triumphs that make everything worthwhile.

When I told my Mum I’d got the job I could hear the relief in her voice: she knows I love loud, gobby teenagers and fast, frenetic workplaces. My eldest sister, a novelist, told me she’s proud her brother’s a teacher - or, as she puts it, “a professional good person”.

More than anything else, I can’t wait to get back to London, the best city in the world. I know it can’t last, but my God, the rose-tinted specs feel just right for now.

The writer, who wants to remain anonymous, starts as a head of year in a London comprehensive next term