The Coolidge Effect.

Former US president Calvin Coolidge and his wife visited a poultry farm. During the tour, Mrs Coolidge noticed roosters mating frequently and inquired how often that happened. The farmer proudly explained that his roosters performed their duty dozens of times each day.

''Perhaps you could point that out to Mr Coolidge,'' replied the first lady.

On being told, the president asked the farmer, ''Does each rooster service the same hen each time?''

''No'', replied the farmer, ''there are many hens for each rooster.''

''Perhaps you could point that out to Mrs Coolidge,'' replied the president.

I love that story.

This is knifey, from 'the internet'.