“Hi, yeah, we’ve got a girls’ school for you this morning - really nice, it’ll be a holiday,” says Josh, the guy from the agency, as he sends me off on my supply teaching assignment for the day.

“Erm...OK...I haven’t been to one before,” I say. “Is there anything special I need to know?”

“No, nothing at all. They’ll be great, it’s a lovely school - just teach them some science.”

I step out of the front door and check Google Maps for the location of the school.

“Of course there’s nothing to worry about,” I say to myself as I jog into the school grounds. “Girls are supposed to be ‘easier’ than boys, right?”

Well, sort of.

I’m not long into the school day before I realise what I’ve waded into. It’s not that the girls are unpleasant, as such (supply teaching certainly feels safer without the bristling aggression of the boys). But somehow, when you throw a lot of girls into one place, with no balancing forces, they are just wildly unpredictable.

‘You don’t know what girls are going to do next’

I’m never quite sure when they are all going to burst into a rendition of Katy Perry’s Firework or start to grill me about what part of the world I am from, rattling off an impressive list of exotic countries. Weirdly, they don’t ask me what religion I am - a question all the boys ask. 

With boys, you only have to watch those one or two characters who are looking for opportunities to annoy other members of the class, and the job is pretty much done.

But with girls, working out what they are going to pull next really is an impossible guessing game. My wife complains that I lack emotional intelligence, and I start to think she might be right.

There is also the minor terror of being the only man in a room full of women. I feel concerned about how easy it would be for them to make a false allegation against me.

I am lost for words and totally disarmed when one insists she is going to the toilet “to change my pad”. Did one of them really tell me that? I want to melt into the floor and never come back, and she knows it.

‘Constant sense of unease’

After my day in the girls’ school, I am fried. The constant sense of unease has worn down my nerves. Novice’s exhaustion, I hope. I write a note-to-self: “Research Amazon for the manual that tells you how to deal with larges masses of teenage girls.” There must be one, surely?

There are many supporters of all-girls’ education - and there is evidence to suggest that some girls get on much better in traditionally “male” subjects, such as physics and maths, if they are taught in single-sex schools.

This may be true, but I’m not sure it’s something we should really be pushing for more of. There’s a reason the world is half male and half female, and it’s called balance.

Girls’ schools are way out of balance and knock this supply teacher off his perch.

But there’s always tomorrow. At least in a girls’ school, you never quite know what the next day will bring.

Katy Perry song, anyone?

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