For many Westerners, Christmas is intimately associated with excess — Santa doesn’t have the physique of a man who is watching his calorie intake. It is the season to be jolly, not the season to worry about your weight, credit card debt or wasted packaging.

The same was true when I was growing up in Scotland. Santa brought an amazing array of chocolates, books, toys and games. One Christmas morning I sat stuffing my face with sweets and piling my presents into a tower. Then a thought occurred to me.

“Daddy,” I said, “this doesn’t seem very fair. Santa’s brought me a lot of things, but I haven’t gotten any presents from you.” I paused. “I’d really like a new bike, actually.”