The other evening I nearly had the top of my head shredded by a buzzard. Relations between the bird and me had, admittedly, been difficult for some time.

It all began a few weeks ago. I would get home and set off for a jog, intent on clearing away the summer-term accumulation of classroom fug. Each time I passed through one particular field, the buzzard would make its rather tiresome, look-at-me “keeow” sound from on high and then begin silently following me. Whenever I stopped to confirm the pursuit, the bird would immediately stop too, almost as if we were playing an avian variation of What’s the Time, Mr Wolf?

But this proved to be no parlour game. The bird took to swooping over me. Nothing too close at first but then, on this most recent encounter, I noticed the ground beneath me suddenly darken under the shadow of its wingspan. It was surely coming for me this time.

I threw myself into a neighbouring field - even at the time reflecting, as I lay sprawled among the oil-seed rape, “I guess this is why I’m not super-head material”. But if I had not hit the floor I am fairly sure those talons would have sunk into my skull and that I would now be the only teacher in the world with a bird of prey’s signature permanently etched into his cranium.

And there would have been no way of concealing the incident from my classes. For although the cartoon at the top of my column bears very little resemblance to the real Stephen Petty (if only I looked half as good as this hunk), it does have me right in one respect: I am bald. There would have been no hiding the buzzard story away under a thick mane of hair.

Would I have felt able to carry on? Well, I could probably have coped with the indignity. And I would have got used to generations of classes never really listening to me again, their thoughts quite understandably focusing more on my corrugated pate and bizarre life story than my lessons. The really upsetting thing would have been my classes finding out that I was a jogger.

My running is a very precious, personal thing. It is the one aspect of my life that I keep in a completely separate compartment from school. It is my guaranteed sanctuary, my cherished midweek break and my weekend retreat. I run in part to keep physically fit but it is more about keeping a balance, about casting aside the regular teacher anxieties and allowing other things to overtake for a while.

My iPod plays a crucial role on my run. I use it to tune in to an audiobook or perhaps a podcast - anything from Melvyn Bragg discussing some obscure ancient Egyptian poem to some comic punditry about England’s World Cup prospects.

I believe teachers should book these regular escapes at least twice a week. Hoping to “hang on” until the next big holiday no longer seems self-protective enough in a job that - rather like that wretched bird of prey - increasingly “keeows” at us from on high and follows us around wherever we go. We must not let the talons of torment sink in, for there really are some sad and serious consequences if we do.

Stephen Petty is head of humanities at Lord Williams’s School in Thame, Oxfordshire