‘Fingers on buzzers!’ says Jeremy Paxman on University Challenge. But technically this is inaccurate. Only one of the teams actually has buzzers. The other side has push-button bells, instead.

I’ve been watching the programme religiously for God knows how many years without ever consciously noticing this. But, once you’ve been told, it’s obvious — in much the same way it’s obvious that the way you tell Thompson and Thomson apart is that one has an upturned moustache and the other doesn’t.