. . .as I have been of late I wondered about the origins of the phrase and discovered, like so many colloquialisms, that it derives from a truth, in this case being the fact that hatters frequently suffered mercury poisoning (used in the manufacture of felt during the 18th/19th century) (traditionally, top hats were made with beaver felt), and absorption of mercury through the skin can cause Korsakoff's syndrome - a form of dementia
but, not one to stop at the first hurdle, I dragged myself off to the cinema to carry out further investigations into the madness of hatters. . .
(don't you think that his tie reminds you of liquorice allsorts. . .)
I can't recommend Alice In Wonderland mainly because having now seen one I can say that I don't really like 3-D cinematography (too much like walking thru a dusty attic full of cobwebs), and there was one truly truly dreadful bit which made me cringe, but I'm glad I saw it as I like Tim Burton and his wife and, of course, the delectable Johhny. . .
my favourite character was The White Queen