"We're not very popular at the moment"

Just watched Cameron on Letterman.   This is the moment when he responded to the question, "How are you doing ?"   Many people have commented on his failure to translate the words Magna Carta, which is bizarre given his Eton education and, anyway, why couldn't he guess ?   Boris, of course, would have known.   Cameron did, however, work in one of my favourite historical facts, that the British sailed up the Potomac in 1814 and burnt down the White House.    I also noticed his mistake about the royal family.  He said that the Queen's visit to Ireland this year was the first by a member of her family since Irish independence.   Has he forgotten Lord Moutbatten ?