I followed a wonderful British-American thread on Blurt yesterday, discussing "Two nations - divided by a common language," which made me think of this British saying from the classics of Ask.com.
It dates from British author Margery Allingham, her 1938 mystery novel THE FASHION IN SHROUDS. This staple of the Queen's English is now enshrined in the Yale Book of Quotations, as well as MAD Magazine 1950's.