Here we are, eight or so weeks into the new school year, and I’m on my knees. Am I a 22-year-old newly-qualified teacher, exhausted in her first full-time teaching job? No, I have years of teaching experience - but solely in the private sector.

I had a snug little job - nice girls, lovely class sizes, able to teach my subject. But when the work dried up, I moved to a local comprehensive. It’s a good school, well thought of, but I am squeaking with tiredness after 12 lessons a week. And I feel like a novice, as though I’ve never even done a minute’s teaching. The learning curve is alarmingly steep.

The school I have gone to is a good one; I have never met such solidarity in a staffroom. The staff are dedicated, cheerful, efficient and professional, and I am awash with admiration for them.

I am learning from them as fast as I can gawp through their often open classroom doors. My inspiring head of department doesn’t need any more student teachers, yet helps and guides me as though I were one.

No, it’s the children I find so tiring and demoralising. In private teaching, it seems, I didn’t learn enough classroom (and child) management skills.

Mind you, if I’d wanted to be a policeman I’d have joined the force, but I prefer teaching.

These students have seen it all, done it all - nothing is new or exciting. One cannot blame the teachers; our soundbite culture makes it difficult for pupils to concentrate or want to go deeply into anything. Everything’s “boring”.

Year 7 are still fun - sitting still for a few seconds, listening. But for Year 10, it’s a matter of engaging them every few seconds, working hard all the time to keep their attention, because they are not keen to be there.

Even if I offer exciting alternatives - videos, outside speakers - it’s not novel. They’ve been there before. They have acquired a layer of cynicism and seem impervious to a lot of what I want to teach. But I have to get beyond simply frightening them with the necessity of passing this particular subject. I want them to think.

This is hard work. They are bound to find it boring asthinking doesn’t come instantly or easily to them. Short of dancing on the desk or popping my head through a cardboard box, how can I engage the attention of those who want to be elsewhere? After two minutes I would be old hat anyway. The question is - am I a good enough teacher for the state sector? I shall have to learn fast and increase my stamina. Or admit defeat.

The cheerfulness of my colleagues amazes me - the care and concern for each child, and the lack of moaning (there’s no time!) about overwork in the face of the demands of the national curriculum. Their cheerful confidence and their dedication to help children in huge classes (well, huge to me - 27-ish) amaze me. I’m staggered that there are so many excellent teachers who are still willing to work long hours for fairly indifferent pay. These teachers deserve open-mouthed praise; they are under fire! My blood boils at the idea of being “judged” by performance. I’d like to see any politician survive an hour with my Year 10 group with his or her self-confidence intact.

My steep learning curve is less about my subject than about learning how to control a class. It’s not what I went into teaching for. No wonder I went into the private system years ago. No wonder that, for my health’s sake, I’d go rushing back if another cosy little job came up. Look at the material differences: private schools are often carpeted, with a hushed atmosphere. There are quiet, tidy and generally well-motivated small classes.

There may not exactly be “silken girls bringing sherbet” but quiet staff shimmer in, smoothly wheeling in trolleys piled with cups and saucers, pots of coffee and tea, snacks and biscuits. At the high school, we select a mug from an indifferently rinsed pile, pop in a tea bag, get the urn to squirt and reach for the plastic milk bottle.

But there’s simply no time for backbiting or intrigue - the children are the whole focus of concern and I keep hearing “we’re all in it together”. Like fighting troops, there’s solidarity among us. I know which group of colleagues is more worth having. But will my lack of learned stamina force a retreat?

Christine Shepherd teaches in Malvern, Hereford and Worcester