Canadians, Pierre Berton writes, are not only a winter people but are also, by reputation, a wintry people, 'frosty of mien, cool of temperament, chilly of countenance. . .not given to public displays of hot emotion' - except at the hockey rink, when players bash each other and the crowd calls for blood. And that, he says, is just part of the paradox of our most fascinating season.