Hi, you’re through to Gemma’s answering machine. Sorry, there’s no one here to take your call at the moment. Please leave your message after the tone. But wait. If it’s 3.45 in the afternoon, and you are one of my so-called friends, please don’t leave a message. Please leave your office and go and throw yourself under the nearest bus.

“I hate to sound rude, caller, but I’m sick of it. You think that just because I finish school at 3.30, I pack my bag, jump into the car, arrive home and then settle down to a relaxing afternoon watching re-runs of Crossroads on Sky Gold before I whip up a cordon bleu meal for my supper. Let me explain something that I think is going to come as a bit of a shock. Here goes. Just because the kids go home at 3.30, it doesn’t mean that I do. In fact, at 3.30, my day is just beginning.

“It’s a popular misconception about teaching. You don’t understand what we all complain about because we work really short days and get really long holidays. You think that when that last bell goes, the sofas in the staffroom fold into the wall, a bar pops out of the floor, and we all start doing the lambada with cocktails and bowls of olives. Every time I get in from school I have loads of messages on the very machine saying ‘Hi Gem, where are you? School finished 15 minutes ago. Are you stuck in traffic? Just calling for a chat. Bye!’ Let me enlighten you.

“At 3.45, I’m still involved in complex negotiations with my form, WAR 10, regarding putting their chairs on desks and transferring their mountain of crisp packets from the floor into the bin. It’s a delicate process. Then we have a quick chat regarding outstanding homework, and the progression of various relationships and who’s broken up with whom. This could involve up to three cups of coffee (that’s two sugars, Miss, if you’re making it) and at least one box of tissues.

“Then I deal with the mountain of memos that have built up on my desk. Then I start to think about some marking. That starts a process of denial that might last anything up to an hour. Then I plan my lessons for the next day. Then I knock together a couple of worksheets. Then I break the photocopier, and spend half an hour apologising to irate members of staff. Then I might think about coming home. Then I remember that I promised to clear out the book cupboard help put up some postersmoderate some exam scriptswatch a netball match plan a scheme of workwater the plantsfind someone’s gym kitread a 19th-century novel we’re planning on teaching. So I stay for a bit longer.

“Can I point out something caller? If my day is so easy, how come you’ve got hours free in the middle of the afternoon to call me for a chat? Unlike your day in the office, the school day just isn’t cut out for socialising, unless you’re really into younger men. And I mean much younger. So stop calling me in the middle of the afternoon. I’d love to discuss your complex gynaecological problems and why Greg isn’t making you feel special any more, but I’m actually at work at the moment. Teachers work too - got the message?

“Please speak after the tone.”

Gemma Warren teaches at The Latymer School, Edmonton, north London