In the UK it was “Attack Henry Cooper, outside his shop, on a Tuesday” no idea why the random violence but I never forgot it

For me, UK, posh school, 1980s it was just "sohcahtoa" - easy enough to be its own mnemonic. No need to gild a lily.

Your order is cosine, sine, tangent - CST. A quick look at the other examples here seem to prefer SCT - as do I but only because that is what I was taught.

I also note your mnemonic is very different to the one I learned in having the function name last. So AHC vs CAH.

There is no right or wrong here but I'm sure we can agree that there are loads of mnemonics for these basic trig formulae and nationality isn't involved.

Allegedly your grandpa, armed with his slide rule, has even more random violence:

"Spitfire or Hurricane come and hurry to our aid"

This works for me as the order of the functions matches the order shown on my trusty FX82A. Your version is kind of messed up.

I am giving this AI thing a wide birth, however, could we ask a LLM to invent a new aide memoire for this? We have got the silent generation and the boomers covered, but is there something we can do for kids today? Maybe it references Cinnamoroll, Hello Kitty or Octonauts characters that actual kids know, without it being ultra-violent.

UK, state school: “some officers have coaches and horses to order about”