missprim - I can see the headline now 'Dope-smoking sex change history teacher unmasked by sleuth on Q&A website'. But no, it wasn't me. I just remember lcg saying that she grew up in Stroud, which is full of eccentrics, weirdos and pot-heads.
I don't remember any particular school pranks, but I do remember one lunch time a friend and I accidentally-on-purpose locked ourselves in an upstairs tutorial room to avoid a domestic science lesson. We did this by unscrewing the door handle on the inside, although I can't remember what we found to use as a screwdriver.
After a few minutes of thinking how wild and rebellious we were, the penny dropped and we realised that we were actually trapped in this room. Doh! As panic began to set in, I decided that it would be possible to climb out of the window, onto a gable over a downstairs window and slide down to freedom. My friend was having none of it, however, so I decided to go on my own.
Unfortunately a particularly fierce maths teacher was teaching in the room below, saw my legs dangling over the classroom window and my ungraceful slither to the ground. 'You, girl, come here!' came the dreaded cry. All I could do was ham it up shamelessly, saying how the door handle had come off, we'd been trapped for ages, we were terrified, I thought I'd die climbing down from the window, and my friend had fainted, etc, etc. The teacher then ran upstairs, liberated my friend, who'd heard my performance and promptly did some very convincing swooning.
So we were taken off to the school secretary's office and given hot sweet tea, the headmistress sent out for some sandwiches for us as I'd said we'd been trapped for an hour and therefore would have missed lunch (which we hadn't), and the caretaker was asked why the door handle had been loose in the first place. (He was a miserable old git, so I don't feel bad about getting him into trouble.)
And we missed the domestic science lesson. Result!