You can always tell when it's a pupil's birthday by the number of sticky cakes smuggled into the library.
"Can you eat that outside please?" I say - but birthdays are special and I can't bring myself to forbid the eating of celebratory food just because we're in the library, so I usually content myself with a feeble: "Well, make sure you don't get any on the books."
Then, if I want to know how old they are, I simply ask: "Driving lessons?" If they nod, they've just turned 17. If they look aghast at the idea that they might not already be seasoned drivers, they're 18. And if they're 18, they're soon to be faced with their first opportunity to vote.
"Who are you voting for, Miss?"
"People don't usually say who they're voting for," I reply.
"Yes, but really, who are you voting for? I can't decide. They're all wankers as far as I can see and none of them cares about us."
"What makes you say that?"
"Well, they wouldn't go on about hoodies if they cared - it's the politicians who've given us all a bad name. And anyway, they didn't have to pay to go to university. It's so unfair."
I retreat to my desk to ponder this surprisingly impassioned speech.
Surprising because I didn't know they cared. Their lives at the moment are governed so oppressively by the A-level revision timetable that I'm amazed they've found the time to formulate any views at all.
I'm encouraged that they have fire in their bellies. But I feel a bit depressed: I feel we may have let them down before they've even started and I don't remember feeling let down at that age, not by the Government anyway.
I see the speechmaker again later on. "I think you should vote," I say. "You obviously care about the world - your world, anyway - and it's up to you to go for whoever you think is most likely to run things the way you'd like. Nobody's perfect."
"My mum is," he replies. "She made this birthday cake. Here, have a piece Miss, it's wicked."
Claudia Court, Secondary school librarian.