I flicked through a book in a charity shop once, called "Lies to tell children"
(or something like that.)
My favourite was "Wine makes mummy clever".
( Moon Girl Technologies don't take my word for anything, Wed 23 Jan 2013, 14:00, Reply)

Lies to Tell Small Kids
By Andy Riley of Bunny Suicides fame. Excellent book, my favourite is "your grandmother is a cold war sleeper agent, who is programmed to destroy all humans. her code word is badmington."
(DonMorte use your nonce-sense, Wed 23 Jan 2013, 23:47, Reply)