" I remember once reading that the tenth Duke of Marlborough, on a visit to one of his daughter’s homes, announced in consternation from the top of the stairs that his toothbrush wasn’t foaming properly. It turned out that his valet had always put toothpaste on his brush for him, and as a consequence the duke was unaware that dental implements didn’t foam up spontaneously. I rest my case. "
― Bill Bryson , Notes from a Small Island