Tales from the Water Cooler: The joke that made me feel old

There are lots of childish jokes in Channel 4's new university sitcom Fresh Meat, and I chuckled at them all: pen-cocks, poos and glory holes.

Yet it feels like a rare youth-based dramedy, in that adults don't have to channel their inner teen to enjoy it. (Parents loved Skins, but largely as a research tool to help them understand their children.) It's set during Freshers' Week, the first opportunity many of us have to decide who we'll be as grown-ups. Instead of being forced into friendships by circumstance, like The Inbetweeners, we're finally allowed to pick our allies. Fresh Meat's characters are starting to learn about mature relationships; some of us are still learning. I graduated less than a decade ago, and am neither teen nor parent. But I'd convinced myself that I was still, broadly speaking, of same generation as an undergrad. Until the Harry Potter joke, that is.

"We're very Hufflepuff here," Kingsley the in-betweener told JP, the monstrous posho. "Wouldn't you be happier in Slytherin?" All at once, I could see the clear divide between the children of Hogwarts, and those who can recall the last great REM album – and that I was trapped on the far side of it.

Harry Potter existed when I was a fresher. Just. But back then it was merely another popular childrens' book, and discussing it with a fellow student (let alone my English tutors) would have been eccentric, to say the least. For today's 18-year-olds, Potter is as permanent as Dickens, or Star Wars. So anyway, it was a good joke – but it was one of the few that didn't make me laugh. Laugh? I nearly cried.