Last week I walked into the staffroom and caught someone drinking from my mug. In the official league table of personal violations, unsolicited borrowing of crockery ranks alongside being burgled, phished or having your eyeball licked by a stranger. Granted, it's less likely to end in eye chlamydia (now alarmingly on the increase among Japanese teenagers) but it does cause undue distress. It was a truly upsetting incident - like the time I went into the bathroom and found my husband standing naked in the shower, scrubbing the mildew off the tiles with my toothbrush.
Teachers are usually more respectful of other people's stuff. Teaching feels like a production-line career, so any individualisation of the workspace becomes disproportionately significant. Another teacher's board wiper may look like an ordinary dishcloth but if they brought it in from home it's a heraldic coat of arms. Little wonder they go mad when you stuff it in your bag.
Children are similarly proprietorial when it comes to where they sit. They will begrudgingly obey if a teacher asks them to move seats but when another child wilfully takes their place it erupts into all-out war. "Miss, Miss, he's in my seat again" is the oft-heard plaintive cry of a child whose school life is so micromanaged from above that a scuffed plastic chair is the last thing he can control.
My reaction to another teacher using my mug was similarly indignant. Because autonomy is on the decline in schools, we fiercely defend our remaining personal freedoms. They can take our pensions, our health and our work-life balance but they'll never take our Cath Kidston mugs.
At home, my eldest son is waging similar territorial battles. His belongings - stockpiled from four years at university - are seeping through the house like a stain. The biggest problem is the ancient set of golf clubs blocking the hallway. When challenged, my son points to his cramped single room. His cupboards are already bursting; where else can they go? I offer to decant them to the garage but he clutches his 4-iron like a child clinging on to a chair.
I understand his frustrations. When you have no control over your environment, you feel alienated from the world. Such alienation happens all the time in school. I wonder what psychological damage we do when, under the auspices of doing good, we score out students' ideas in essays and replace them with our own. When sub-editors similarly "improve" my work, I feel like giving up writing and baking scones instead, so our savage editorial intrusions must batter the self-esteem of the young people in our care. "Killing your babies" is a tricky enough act for a writer but, as food critic Giles Coren once pointed out, having them fucked over by someone with a machete, a chainsaw and no ear for metre opens up whole new levels of pain. Compared with which, having the odd biscuit dunked in your mug is not much to complain about.
Anne Thrope (Ms) is a teacher in the North of England. @AnnethropeMs.