I’m trying to lose weight. I’ve been doing Weight Watchers for the past six months - going to the gym, keeping a food diary (and not lying too much in it), visualising myself being thin, and trying to work out my true motivation for eating the whole time. The books all say I’m eating so much because I want to feel loved, and because I’m bored and need to plug the gap with fatty snacks. But I think I need to eat the whole time to put off marking 62 exercise books and drawing up a provision map. But I’m only a teacher, so what do I know? I’m also trying to cut down on the number of books I order from on-line book shops. And I’m trying to stop buying “vegetable medleys” from the supermarket every week, thinking that I’m going to transform them into a healthy stew, but then watching them go mouldy in the bottom drawer of the fridge while I make another vat of pasta. In short, I am trying to inject some discipline into my life.

What’s strange is that if you asked any of my colleagues in school to describe me in a few words, I’m sure one of those words would be “disciplined”. I’m not prepared to guess what the other words would be, but I’m pretty certain they’d think I was good at getting myself moving. I am the kind who gets things done. If someone gives me a form to fill in, it gets sent back quickly. If I need to ring a parent, Ido it within 24 hours. I never leave something I’ve been dreading; in fact, I’ll tackle that job first, just to know it’s out of the way. I put all meetings in my diary. I write two-week warnings when I have to get reports done. And I even stick articles about special needs on the back of our office door. I am a right little goody two-shoes. And sometimes it doesn’t help. Ultra-organisation can leave you being inflexible when plans change, and being too anal about your routine is difficult when teenagers are likely to throw the unexpected at you. But I think I’m pretty good at getting my job done.

So why can’t I extend this discipline to other areas of my life? Why can Ispend six hours producing a fully frameworked scheme of work, yet crumble at the sight of a chocolate biscuit? How come I’m not put off by plodding through endless DfES circulars, but can’t resist the idea of ordering another cookery book online even though the 5 per cent discount is wiped out by post and packing? Could it be that I’m using up all my discipline reserves in one area of my life, and so have none left to help cut back on the pasta? Is discipline an exhaustible quality? Once it gets used up for the day, is that really the end of it?

Since I started teaching, I’ve always operated a bizarre system of rewards with myself: “One more set of books marked and you can eat that Mars bar.”

It’s the only way I can motivate myself to get any marking done. This has led to my being super-efficient with my work, but weighing two stones more than I want to. I worry that needing so much discipline to get me through the working day might mean that I’m in the wrong job. Or, of course, it could mean that I’m not as disciplined as I thought I was. I do like doing tasks associated with my job - I just don’t like giving up Mars bars. Maybe I should forget this whole discipline issue and go back to getting my marking done. And enjoy being wobbly. We can’t all be perfect all of the time.

Gemma Warren is an assistant special needs co-ordinator at a London secondary school. Email: gemmablaker@hotmail.com