It’s winter, the street lights have haloes in the fog and I don’t think I’ve seen the sun for a week. I get up and drive to work in the dark. This is adversity and grind and it’s precisely the time when we all need a lift.

I offer you here two tales from my classroom to help shake off the drudgery and raise the spirits, incidents in which children have impressed, surprised and fired my flagging sense of awe.

For the first, I need to set the scene. My school has just radically altered the way that personal and social education (PSE) is taught. Previously, often reluctant form-tutors taught it, mumbling without enthusiasm about sex, old people or moral values before handing out badly photocopied worksheets and telling students to get on with it.

In the new system, a designated team who volunteered to teach the PSE programme are, without self-consciousness, getting students to form circles and talk about anything from bullying to job hunting.

It was with one of my PSE classes that I found the first reason to feel inspired. The subject was self-esteem and personal qualities, and I had decided that it would be good to ask the students to talk about some event which had profoundly affected them. I was all set to talk about the death of my grandad, or my wedding day, but then the kids started talking and there was no need for me to fill the silence I’d feared.

The class listened as Simon told us about his mother’s death and when David shared a similar bereavement I remained silent. Then Jodie’s hand went up. She talked passionately, railing against drugs and drug-taking and how that culture had ruined her mother’s life. As we listened, we all knew that Jodie lived in a children’s home and hadn’t seen her mother for years. Pauline was next. She talked in a whisper about the day her father had abducted her older brother but did not take her. When she had finished it was quiet in the room.

There was more to come. Stories of dying uncles and aunts, family rows and divorce. I left the room deeply moved and went to teach Newton’s laws to a GCSE science class. It was very hard to concentrate.

The second tale is shorter and is, I’m sure, repeated in classrooms everyday. It is a story of courage.

Mandy, a cripplingly shy 15-year-old, is standing in front of a classful of some of her most difficult and cynical peers and presenting her work on the human kidney.

She’d drawn overhead projections and she’d written a script. She read it haltingly and had some problems with the terminology, but she successfully negotiated “glomeruli”, “Bowman’s capsule” and “medulla” to finish pale-faced and smiling. An incredible achievement.

At such moments I have this phrase rise to my head unbidden: “This is what it’s all about!” I say to myself and of course it is. A-Cs are important, quality teaching and learning crucial, line management, resources and development plans all have their place. But for most of us, it is for these marvellous moments that we are in the job. Ordinary children in ordinary classrooms doing extraordinary things.

Andrew Wright is head of science at Angley School, Cranbrook, Kent. The names of the children have been changed.