For something that happens every year of our lives, we really don't know much about Christmas. We don't know that the date we celebrate was chosen by a madman, or that Christmas, etymologically speaking, means "Go away, Christ." Nor do we know that Christmas was first celebrated in 243 AD on March 28--and only moved to December 25 in 354 AD. We're oblivious to the fact that the advent calendar was actually invented by a Munich housewife to stop...