When my maths teacher was introducing us to functions, she wrote f(x) on the blackboard and informed us that it was pronounced "f of x". I shared a desk with a boy called Scott, who thought she was telling a letter of the alphabet to "f. off".

He spent the next hour repeating "f of x! f off x!" - experimenting with the delicious phonetic closeness of the two words - and giggling helplessly into his own neck. No-one else laughed at all. We were 14, and most of us were quite accustomed to telling people, things and abstract concepts to fuck off.