Their best lesson is always doing lunch
It is only natural. The overriding evolutionary imperative for the young of any species is to eat to survive. It is not surprising that schoolchildren are more preoccupied with food than the niceties of Palmerston's foreign policy.
In West Wales, in the 1960s, my teachers seemed to have grasped this fundamental biological fact. They knew that, for the young hunter-gatherers in their charge, lunch was not just a break from the serious business of the day, it was the serious business of the day and should be treated as such.
It was a bilateral school, that is, a bog standard comprehensive, but the midday meal was conducted with the formality, ritual and sense of occasion that you would normally expect in the officers' mess or an Oxbridge college.
Grace was always said in Welsh - it was an English-medium school but we never doubted what language was spoken in heaven. Then the teacher on duty took on a role which combined that of maitre'd, mine host and prison officer Mr McKay, orchestrating the whole event and stamping his or her personality on it.
A few of them took the opportunity to do a little unobtrusive counselling.
One saw it as her mission in life to teach us the correct way to hold cutlery. One insisted on a monastic silence throughout. Another table-hopped, trying to get us to indulge in a little urbane conversation.
But it is not easy to exchange badinage when you are folding a forbidding expanse of pork luncheon meat into your face or taking forensic pokes at a slither of gristle to ascertain if any part of it might be edible.
Just as challenging was the stew that could only be eaten with eyes closed for fear of seeing what was floating in it or, on Fridays, what Nigel Molesworth described in Down with Skool as "the piece of cod that passeth all understanding".
And sometimes we were served a cawl that would have attracted the attention of Dr Hans Blix. It induced such chronic flatulence that, in the afternoon, every classroom seemed to house a brass band tuning up.
I am sure that school food tastes better nowadays but, according to the recent deluge of reports and surveys, it is scandalously unhealthy. Indeed, read some newspaper headlines and you get the impression that a typical school lunch is as full of natural goodness as a pack of 20 cigarettes.
Healthy Eating amp; Sustainable Food Chains, published last month, explains why kids are being fed what the Soil Association has called "muck from a truck". The author, professor Kevin Morgan of Cardiff university, concedes that school cooks perform a minor miracle every day but that they are hamstrung by the over-zealous implementation of the EU's "formidably arcane public procurement directives".
These oblige local education authorities always to opt for the lowest price regardless of quality. So Welsh children, born and raised in a country that prides itself on being the bees knees when it comes to food production, are being served up a menu of untraceable, over-processed gunk. The unit cost of a school meal in Wales is 35p. If the cooks can perform minor miracles with that, think what they could do with five loaves and two fishes.
Things can only get better - politicians, pressure groups and parents will make sure that they do. In fact, there is now such widespread concern that kids can expect to share their canteen with a melee of tut-tutting Welsh Assembly members, dieticians, local food producers and Jamie Oliver.
I am sure they will sort out the menus. But I am not so sure that they will appreciate that for a school meal to be good, it needs more than an acceptable balance of protein, fats and carbohydrates. It needs to be celebrated as the big event in the timetable. And 40 years on it is what pupils will remember best about their time in school.
Arnold Evans is a Cardiff-based journalist