I've just finished Extraordinary Popular Delusions and the Madness of Crowds, which is something of a cult classic amongst people of an atheist or skeptical persuasion. Written by Scottish author Charles Mackay in 1841, the book details some of the bizarre things that people had believed and done over the preceding centuries.
It's best known for its chapters on outbreaks of mass irrationality, such as financial bubbles like the Tulipomania, the European witch trials, and "animal magnetism" (the sections on which include some excellent descriptions of psychosomatic illness and the placebo effect). Heavy stuff.
But my favorite bit was the charming "Popular Follies of Great Cities", which covers the spread of comedy catchphrases in 19th century London. Remember when everyone went around saying "Wasssssssssssupppppppp?" or "Doh!" or some variant of "Your mum / yo momma?" (that last one is still going on). It turns out this is nothing new.
Two hundred years ago Londoners, at least working-class ones, were fond of such phrases too. There was the question "Who are you?", which could be aimed at anyone doing or trying to do something above their station; the universal answer to any stupid or unwelcome question, "Quoz", and best of all, "Has your mother sold her mangle?" the implications of which Mackay does not discuss in detail.
Each of these were popular for a few months and then went out of fashion. Personally, I think it's time we brought some of them back into use. So - has your mother sold her mangle? I thought so.