On the 5th day before Christmas... it's the last posting date for first class mail
It's your last chance today to send a small piece of folded cardboard to somebody you've not communicated with since last Christmas. Better hurry then, because the last collection round your way is probably at noon-ish. Miss the deadline and your festive greeting will be stockpiled in a huge warehouse until mid-January, by which time the intended recipient will no doubt have crossed you off their Christmas card list for good.
It was Sir Henry Cole who sent the world's first Christmas card exactly 160 years ago, using the new Penny Post. Sir Henry thought his friends would appreciate a three-panelled card depicting a smiling family bearing the inscription 'A Merry Christmas and a Happy New Year to You'. He did not, so far as we know, send them pictures of an obese Santa stuck down a chimney, a robin smothered in glitter or Homer Simpson pretending to be a reindeer. As a reward for his good taste, Sir Henry went on to become the first director of the Victoria and Albert Museum.
The Royal Mail now moves over a billion Christmas cards each December. That's because there's still nothing to beat receiving a real card through the post rather than some feeble virtual greeting, not least because it's very hard to cover your mantelpiece with emails. And the annual Christmas card tally remains the indisputable annual barometer of your popularity and social standing. If you receive more cards than you send, your place in society is assured. However, send out more than you receive and the level of your insignificance is made explicitly clear. (Note to self: sent 67, received 23, give up now).
Each year friendships are extended by the exchange of Christmas cards. People we once knew, echoes of former lives, their continuing existence is confirmed by the arrival of a small envelope. If you're really lucky there's one of those thrilling "What a year it's been..." family newsletters tucked inside, full of births, holidays and operation scars. This means that you never have to pick up the phone and ring the other person because you know that everything you'll ever need to know will be safely documented in next year's missive. Of course, the other person's card always arrives the day after you sent yours, so the brief scribbled note inside your card (Congratulations!) can only react to last year's news (I became a grandfather...) rather than the latest bombshell (my wife left me and the doctor had some very bad news...).
So let's all remember Sir Henry Cole this Christmas because it's thanks to him that we remember everyone else. Although I suspect there'd be a whole load more forests still standing if he'd never bothered.