I think you either read Tony's question backwards. He asked how many know that without Looking it up. I said nearly everyone probably know without looking it up.You are never too old to learn. Haven't you ever wondered by your solder is labeled Sn37Pb63 or similar? Why copper content is labeled Cu and so forth? You should read and understand the labels.
I followed up with, only pompous elitists think they get jokes that not everyone else gets when, in fact, nearly everyone got the joke.
Please read more carefully unless you were in the pompous elitist group and assumed only a small group got your original joke - which I now assume was the case.

