Spiked and studded dog-collars derive from the days of the Ancient Greeks, who would give their sheep-dogs sharply spiked collars to protect their necks from wolves whilst they watched over a Sheppard's flock at night.

In 1994, 7-Eleven coined the term "brain freeze." The word was developed to explain the feeling people get when drinking a Slurpee.

All of David Letterman's suits are custom made - there are no creases in his suit trousers.

AMAZING FACTS