When I retire, I want to have some memories…!"

So said "Tim" – the amiable character in Ricky Gervais's The Office – when he tells "Gareth" (the "assistant to the assistant manager") that he want to leave his job, go back to university and find something important to do with his life.

Teaching is very hard work, but when you do retire (and that may be a very long way off) you can look forward to memories that people like "Tim" can only crave…

In 1979 I was doing Victorians with my class of ten-year olds. We decided to put on a Victorian Music Hall for the Christmas show. I was the Master of Ceremonies and donned a handle-bar mustache for the part. We ran the show to a packed house for three nights. Everyone laughed.

Twenty years later, I employed two young black guys who could sing and play the piano to gospel music. Within six weeks they had trained sixty kids to sing gospel. They performed a concert in the local church. Their voices nearly lifted the roof off it. Tears were streaming down my face.

Four years earlier I was sitting on a tube train being stared at by a young black man in a hood. He got up and stood over me. "You're Mr Newland innit?"

I nodded. "Darren?"

"Yeh…" he said. He sniffed. "It was good ya kna..!"

Then the train stopped, the doors opened and he got off.

One day in 1986 I was teaching maths to a group of nine year olds struggling with long multiplication. In the middle of the session, a little boy with a speech impediment starts tugging at my shirt. I turn to him. He is nodding his head vigorously. His eyes and face are beaming. "I get it now! I get it now!" he is gasping with delight.

Seven years later I get an email. It read: "I've googled Mr Newland and got this email address. Are you the Mr Newland who used to teach me between 1980-82? You were my best teacher."

Fourteen years earlier, I am in the Lake District with thirty kids doing adventure sports. One girl who has never been out of Hackney gets lost but finds her way back by asking a farmer for a lift on his tractor. Another who has never seen a horse before, falls off one, but jumps straight back on it. And a boy wakes me up in the middle of the night to tell me: "Sir! I've just seen the stars!"

One day in 1984 a boy with learning difficulties is painting. It's home-time and I ask him to pack-up. He says: "Can I stay here forever? I want to paint for the rest of my life!" Twenty-eight years later, he invites me to his one-man show at a gallery in west London.

Two years before that on a visit to a local museum, a girl notices an old photograph of a railway arch that's near her house. It turns out to be the place where the first British pilot built and flew the first British aeroplane. We visit the site. It's derelict. But we campaign to have it recognised. There's a blue plaque there now.

Five years later, an eleven year-old girl in my class refuses to speak to me for three days. On Friday after school, I find a note tucked under the windshield wiper of my car: It reads: "Sorry about this week. I started. Being a woman."

Last year the same person contacted me to say: "I've been living in Australia but I'm home to see my mum. Can we meet for coffee? I've got a little boy now and I want him to meet my teacher."

Not many jobs demand from you what teaching does. But when you retire, you'll have many more memories like this.

I promise.

• Alan Newland worked as a teacher and headteacher in Hackney & Tottenham for over 20 years. He has also trained teachers, worked at the DfE and the GTC where presents live & debates via social media with students & new teachers the professional, personal and ethical issues of entering the teaching profession.