During the lesson, they would chew distractedly on their Biros, desperate for the bell to ring so that they could pop out the back for another quick fag before PE.
That was the 1990s, though. Nowadays, increasingly unfashionable nicotine addictions are being slowly supplanted by a more socially acceptable, although potentially more disruptive, habit – caffeine. For teachers already struggling to hold their class’s undivided attention for an hour, the rise of energy drinks has been a particularly unwelcome development.
Last week, John Vincent, a restaurateur and adviser to the UK government on school meals, called for energy drinks to be banned in schools, saying their high levels of sugar and caffeine made it tantamount to allowing drugs into the classroom.
Energy drinks often contain more than double the amount of caffeine in a can of cola. A 250ml can of Red Bull or its competitor Relentless contains 80mg of caffeine, about the same as a cup of coffee, with the recommended daily caffeine limit currently 400mg.
Red Bull says consumption of its drink should “conform to a person’s intake of caffeine”. But school pupils often have no history of caffeine intake if they don’t drink tea and coffee.
According to one teacher I spoke to, some children can drink up to ten energy drinks a day, with some newsagents selling cheaper versions for as little as 35p can. Fast Forward, a voluntary organisation that works across Scotland seeking to educate children about healthy living, says that it is increasingly being asked to give presentations in schools on the dangers of caffeine.
Worryingly, the group says children often buy energy drinks because they are the cheapest drinks that they can get their hands on.
It says naivety among children about the effects of caffeine leaves them over-stimulated, irritable and unable to concentrate. There is also a general ignorance about the impact caffeine can have on sleep.
Just as schools can’t stop young people getting cigarettes, they can’t prevent them spending their lunch money on energy drinks at the local shops.
But with school meals still high on the political agenda – the Scottish Government recently announced plans for free lunches for those in P1-P3 – perhaps it’s time we send our kids a message about energy drinks during the school day and consign them to a past of illicit fag breaks and Turkey Twizzlers.