Not sure anybody else will find this funny, but a really old memory just surfaced for no apparent reason, and made me chuckle all over again.
I was doing "A" level Physics (that's high-school level to you Americans, I believe) as a mature student at a local College. One tutor (Mr Bell) taught Thermodynacics , Mechanics , etc. the other taught Fields, Waves, Elctromagnetism etc.
Anyway, one day I attemted to excuse myself, early from one of Mr Bell's classes by saying that I "had to go and see the Electricity Board" (Quite true . They were threatening to cut me off for non-payment of my bill, if I didn't get up there and sort it out fast).
Mr Bell responded with: "Why don't you just go up the corridor and knock on his door, once we're finished?"
I stared at him in puzzlement, then repeated myself.
"Ohhhhh! " exclaimed Mr Bell. "You have to see the Electricity Board! I get it, now. I thought you said you had to see the Electricity
bod." (meaning the other tutor
(Btw, that was back in the eighties. I looked at the modern Physics syllabus , not long ago, and it's radically different, nowadays, completely dumbed down. They've take all the maths out of it! and the texbooks now look like coffee -table books. Heck , those kids will get a shock -and-a- half when they get to Uni)