I'm going to have to visit the loo again, the third time in less than half an hour. A teacher interviewed on the radio during a recent day of strike action would put it down to my age. He thought that parents had every right to be aghast at the idea of their children being taught by someone over 60.
I imagine him bellowing at me: "It's your prostate, grandad. Or an age- related urinary tract infection. What you need is incontinence pants. Can you hear me, old man? IN-CONT-IN-ENCE PANTS!"
It's just my nerves. My wife bought me microlight flying lessons for my 60th birthday. "Get me an experience," I said. "Something that will transport my senses to new heights and leave me dizzy with delight." I was hoping for a whisky-tasting tour of Edinburgh. I didn't anticipate sitting in a box several hundred feet above South Yorkshire with only a pair of flexible wings and a lawnmower engine to keep me from plunging to an early-ish death.
I am reassured to learn that Kevin, my instructor, has more than 40 years' flying experience, including 10 in a microlight. I am less reassured to discover that we both have short-term memory problems and take identical blood pressure tablets. I ask him whether the nausea is altitude sickness. He tells me this is unlikely, as we haven't taken off yet.
What has taken off is the age at which teachers retire. In the UK, it is set to rise from 60 to 65, and to keep going up in line with normal retirement age to 68 by 2044. By 2100, I imagine nonagenarian infant teachers will be modelling forward rolls in physical education classes.
I feel a degree of sympathy towards that striking teacher. The thought of some clapped-out old git who can't open his electronic register and trails the smell of stale urine down school corridors is not a happy one, and could have serious consequences for the quality of teaching and learning. But then, it doesn't have to be that way.
The age of worn-out teachers stumbling exhausted through the day before falling asleep over a pile of marking after midnight is already with us. But it is more to do with inflated expectations than old age. The drive to improve standards by heightening scrutiny and demanding increasingly detailed planning, marking and recording is affecting my young colleagues more than me.
Tomorrow - should I survive today - I will breeze into school with a smile on my face and a song in my heart. Tired eyes will flicker briefly in response to my bright salutations. People half my age who have been awake all night, planning an observed lesson, will wearily acknowledge my wit. Teachers with children they had to drag out of bed at stupid o'clock and deposit with a childminder will wave listlessly as I step over them.
Why is this relic from a bygone age, when lessons were planned on the backs of fag packets, so full of life, while those around him appear dead on their feet? The answer is that I work part-time. Spending some of the week several hundred feet above South Yorkshire in a flimsy aircraft might not have improved my life expectancy, but it has done wonders for my work- life balance.
Steve Eddison teaches at Arbourthorne Community Primary School in Sheffield, England.