Last week I met a child I used to teach. We’ll call him Lee because they usually are. He spent his last term with us propping up the wall of shame or skulking in detentions. In theory he was “improving” his coursework, but in reality he was drinking Red Bull and scribbling tattoos on his arms. Nobody was really that bothered because we already had him figured for a C.

Lee was an awkward character and had a reputation for fighting. I took him for English. After two years of battling, we arrived at a truce: as long as I separated him from the other children and let him eat crisps from his blazer pocket, he would keep his head down and wouldn’t be disruptive. It wasn’t textbook pedagogy, but in his case it seemed to work.

I grew fond of Lee in the end. Knowing him out of school helped; he played for the same under-17s squad as my son and, while his aggression was a problem in the classroom, in rugby it was an advantage. He saved many a match with his heroic tackling and fierce determination to win. If only he had approached life in a similar way I wouldn’t be writing this column.

Lee left school last summer with a handful of GCSEs and we congratulated ourselves on a job well done. It was as well he had found an apprenticeship as he wasn’t on our priority mailing list for a place in the sixth form. I met him again at a match at the end of December. He was looking pretty rough. He confided that he had lost his apprenticeship and had been living on the streets. He’d got off on the wrong foot with his mum’s new bloke and they had thrown him out on his ear. Luckily social services had intervened and secured him a place at a hostel. He played that day with his usual flair, but was hurt in a nasty collision and taken to AE. Afterwards, he just disappeared.

Looking back on it, I think we let Lee down. The problem is that when children’s parents don’t give a toss, then often their schools don’t either. I never saw Lee’s mum on the sidelines at rugby, and she never came to parents’ evenings. So, providing we could milk him for our quota of A-Cs, he was someone we could happily forget.

Unlike “Little Sophie”. Little Sophie is one of those pupils you dare not forget. Her end-of-year target is a 7C but she is flatlining on a 6B. Naturally, mum and dad are concerned. They have had lengthy meetings with her head of year and the deputy in charge of progression. As a result, there are more people involved in yanking up her grades than pulled up the fairy-tale Enormous Turnip. If half this effort went into US President Barack Obama’s campaign, he would easily get re-elected.

Thanks to her parents’ concerns, the school has pressed the reset button on Little Sophie’s entire key stage 3 data, with teachers being pressurised to uplift her grades because she happens to spell “occasion” with only one “s” and doesn’t come to school with nits.

Nobody made a fuss like this over Lee. Last week, when I saw him at the rugby, he wasn’t looking so good. Skinny, sallow-faced and wearing a stained grey hoody, he hovered around the sidelines watching the game. A couple of the parents eyed him uneasily. “You know he’s dealing mephedrone now,” I heard someone say.

It shouldn’t have come as such a surprise. What chance do you have when your mum pimps herself out to her scumbag boyfriend and your school turns tricks for the Waitrose mums?

Anne Thrope (Ms) is a secondary teacher in the north of England. @AnnethropeMs.