Reminded of a story my mother used to tell: of how when she was a fairly new teacher in the 1930s, (and admittedly then you might be forgiven for lack of biological knowledge), one of her pupils complained of a "headache". My mother put 2+2 together and made 6: gave the girl a sanitary towel (remember them?) came back into the classroom to find the girl had strapped it across her forehead.....!