There are various ways to teach about language change and the way words collect new meanings. But announcing: "When I was a little mouse ." to the class isn't one I would recommend.
What I had meant to say was: "When I was a little girl, the word `mouse' meant a furry grey rodent." But it didn't happen like that.
It was a senior moment, one of many these days as I now live in a permanent state of senior momentness. (They are occasionally punctuated by flashes of junior momentness - and I take advantage of those - but this wasn't one of them.)
We had had a good discussion in the first half of this Year 7 lesson about new techno-language. I had asked them which words they thought I wouldn't have known as a child.
Some were a bit off with their guesses: "television?" . "electricity?" . "ark?" But others were more accurate with "MSN", "Facebook", "mobile phone". So, pleased with what seemed a good lesson, I moved on to changes in meaning.
But as soon as I announced that I was once a rodent, the room went wild. It was one of those teacher dilemmas when you know you have made a complete plonker of yourself and have two choices: threaten detentions, or swallow hard and take your punishment.
As it was, they were laughing so much, there was nothing I could do except smile. At least I still have my own teeth - and it's just as well as I was gritting them pretty hard.
It got worse, though.
When the class had calmed down and I got round to the teaching point, it turned out they all thought of a mouse as a furry grey rodent, too, because they hardly ever used a computer mouse. They have got used to laptops and other non-mouse alternatives. So, to them, "mouse" was already an archaism.
I found this hard to believe. "Come on," I urged. "If I said to you that I had been out at the weekend and bought myself a new mouse, put your hand up if you would think I had purchased computer equipment." One hand at the back. Thank you!
"See?" I said, smugly. But she was only stretching, apparently.
It's all going too fast. Just as I had got used to "mouse" as computer language, it's a rodent again.
Just as I had got used to LOL meaning "lots of love", I'm told it means "laugh out loud" - and it's even something you can say to each other as a complete word, as in: "Ha ha ha, that's a funny joke, LOL!"
Pupils even look at me askance if I say: "When you send someone an email", as though I'd said: "When you write a note using parchment and quill ."
I'm going to retire early, sit in my rocking chair and knit. At least if I start claiming to have been a rodent in a former life, everyone will just nod sympathetically.
All is not lost, though. I can still manage soup on my own. And I can get to the toilet in time, as long as I carry off the "I always stride like a power-walker towards bathrooms" act convincingly enough.
And give me a tablet - which will hopefully have gone back to meaning a pill, rather than a computer, by then.
Fran Hill, English teacher at an independent girls' school in Warwickshire.