Idiom: As mad as a hatterOED definition: Completely insane, crazyExample: Everyone says he’s a genius, but I think he’s as mad as a hatter
Method To My Madness
This idiom is probably best known because of the fictional character of the (mad) Hatter in Lewis Carroll’s Alice’s Adventures in Wonderland. However, the idiom pre-dates Carroll’s work and was first used in print in Blackwood’s Edinburgh Magazine in 1829. The saying comes from 18th and 19th century England when the toxic chemical mercury was commonly used in the production of felt, an expensive material used in the manufacture of men’s hats. The people who worked in the hat factories were exposed to this dangerous metal on a daily basis, which accumulated in their bodies over time. This resulted in many workers developing dementia as a result of mercury poisoning, an illness which quickly became known as ‘mad hatter syndrome’. So, this idiom has become a popular way of referring to someone believed to be crazy.