How do you feel when you read about spiralling consumer debt and an incipient recession? Mostly I feel glad I don't have a credit card, and guilty for wishing so hard that the housing market would disintegrate so that I can buy a flat some time before I'm old enough to claim the pension I'd have if I hadn't spent the past decade squandering all my money on frivolities like food and the rent. Then I remember that I could have been a sensible homeowner by now if my flirtation with the teaching profession had been more of a lifetime commitment and less of a cursory smooch in a pub car park.

The Conservative Party reckons that 250,000 qualified teachers are no longer working in schools, and I'm happy to report that I am one of them. Except for the qualified bit, because in my day you could waltz into a public school with a note from your college, and a gentlemen's agreement that you really did have those A levels, and get the job. But nonetheless, I did briefly teach: Latin, Greek, ancient history, and classical civilisation for the dyslexics (who comprised five sixths of my A-level set at one school, lest you think I'm being spiteful. I am, but I do at least have the facts to back me up).

I know why I left the teaching world — I earned enough as a writer not to need the money any more. But where are the other quarter of a million former teachers? How have I not noticed them? Are there train drivers out there giving their tardy passengers the baleful eye and telling them it's their own time they're wasting? Is a store manager at John Lewis likely to snap at any minute and tell a vexing customer that if it's so funny, perhaps they'd like to share the joke with the rest of the shop? Is the waitress at my local café able to create an identifiable work of art using merely sugar paper, poster paints and a halved potato as an ersatz brush?

Teachers should be easy to spot, I would think: the best ones look like they've wandered out from a 1930s novel: they wear an academic gown, or at least an ill-fitting suit, and a baffled expression. They have stout shoes, like closeted lesbians in a Miss Marple mystery (a habit, I might add, that I have yet to break. Even my flip-flops are stout). The worst teachers can be identified with a simple behavioural test: they have an attachment to “their” coffee mug that borders on the pathological. There are chimpanzees smashing the heads of rival chimpanzees into a tree branch that feel less territorial than a teacher does towards his chipped, tannin-stained vessel. And people ask me why I fear tea. The fools.

Michael Gove, the Shadow Schools Secretary, said that “talented teachers are not where they should be — in the classroom, opening young minds to new horizons”. While this is indisputably true, I prefer to think that the runaways have decided to open their own minds to new horizons instead.

I once went to a job interview at a school in Northamptonshire, which precipitated my exit from the teaching profession by about a year. It wasn't the hopeless trudging of the children around the corridors that did it. Or the dead-eyed stare of the head of classics, as he explained that he taught Homer every year, so I would have to do tragedy, although that did feel a lot like a metaphor. It was the fact that they'd brought biscuits into the staffroom, in honour of us, the interviewees. Now don't get me wrong, I'm fond of a biscuit. But the staffroom lit up with excitement, purely on account of these biscuits. Lest you be unsure, they weren't biscuits laced with heroin. Just biscuits. And in that moment, I realised I couldn't spend another second in the company of people for whom a biscuit was a genuine highlight of their day. I had no doubt that I would be dead by my own hand before Christmas.

To plead the cause of the escapees, I might try and ambush a freed teacher, much like tragic Gordon Jackson was trapped in The Great Escape. Only instead of saying “Good luck” as he boards a train, I shall fail to tuck in my shirt near a likely suspect. Or possibly sneak Maltesers out of my pocket and scoff them behind my hand, one by one. As soon as I hear the world-weary voice asking if I brought enough to share with the whole class, I shall produce my net and return him, flailing, to Conservative Central Office. Surely when they see us, our faces aglow with liberty (well, mine will be aglow; his will probably be pock-marked with mesh), they'll let us fly free again.

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