This is the season for planning the trip which will determine whether you end the summer term with a bang, or just slump into convalescence.

To a teacher, all school or college trips are unpredictable; but if you’re lucky, they may turn out to be rather more broadly educational than you’d bargained for.

When Mike from the art department asked if I’d like to go to the Lake District with the students, it seemed like a good way of spending activities week. First, because time and geography had come between me and a bunch of friends who’d spent several holidays hill walking, this was a great opportunity to get back up in the clouds again. Walking is, after all, one of the few physical activities left to those of us who have no powers of co-ordination to speak of.

Second, someone else was organising it. All I had to do, apparently, was be there. When you’ve had your share of arranging study visits and exchanges, the status of mere “helper” has its attractions; your responsibilities will be trivial and nothing will be your fault. It all sounded very cosy.

My theory is that Mike asked me because once, in the snow, I’d come into college in walking boots. He was also new and didn’t know better. People who did tended to gulp their tea when they found out I was going camping. So did I when I looked for the course description in the activities week brochure: nothing about walking, plenty about adventure training... Not for the first time in teaching, I felt like an an impostor.

The list of activities was awesome: canoeing, climbing, abseiling, rafting and something called gill scrambling which made me feel especially uneasy. By the time the day approached, I had resigned myself to “plenty of walking” only to find, as we set off, that we’d all “have a go at everything”. But a miraculous chemical reaction was underway. As the long journey north progressed, and the minibus juddered up Shap Fell, I started to think, “why not?”

The moral of this story is a familiar one to any teacher: other people’s expectations are mightily powerful things. Whether it’s passing an exam or climbing a rock, if someone else expects you to do it, there’s a much better chance you will.

The people who know and supposedly love you, will be the first to snigger when you mention that you might be going abseiling. A stranger, however, doesn’t fully appreciate the extent of your weediness. He or she is therefore more likely to say anyone can do this, so you can.

And so I did. I won’t ever forget that first climb. Several students went before me - and by the time it was my turn a second group had arrived, which meant an audience. But I wasn’t going home without trying it. In case anyone laughed, I pointed out that it had taken me 40 years to get to the foot of this crag. Why? Because I wasn’t that sort of person.

What I discovered is that climbing is the exact photographic negative of all bad experiences of school sport. I’d stopped expecting to achieve anything aged seven when I was dumped in the school obstacle race and came next to last. I was just a nuisance on the netball court, the person nobody wanted on their side.

But when you climb, the only thing people shout at you is encouragement, and they do this liberally. They help you by suggesting moves and pointing out hand or foot-holds which you might not be able to see. And however long it takes you to get to the top, however badly you shake, however inelegantly you descend, you can feel proud of yourself because you know strong athletic people who would never even consider climbing.

Every night, I eased myself into my tent thinking how frightened I’d been and how happy I was. At last, a perk in this job! From the first Monday morning climb, through the abseil and canoeing, to the gill scrambling (which involves climbing up the pools and cascades of a flowing river), I was buoyed up by a wave of gratitude to all the people who had let me do this.

After all these years of teaching, too, it was the students who were helping me, holding my boot so that I didn’t slip on a wet rock, hauling me up, telling me what to do and how to do it.

Anyone will tell you that the adventure sports are great confidence builders for your students, that this kind of residential is worth a week of missed lessons because the experience can fundamentally alter the way they think about themselves and even their behaviour.

Now, on Monday nights, I go to the wall - the climbing wall, that is. I’ve at last found a sport I enjoy and which it’s feasible to do after a lifetime’s physical neglect. I’m no longer a weed. I’m a climber.

Gill Pickard is head of languages at South East Essex Sixth Form College.