It isn't the changing seasons making you grumpy, it's the year-long commercialisation and exploitation of any excuse to try to sell us stuff we neither need nor want, by trying to make us think we do need it and want it.

What became of the "twelve days of Christmas"? Before we even get to New Year, "Christmas" is swept away, decorations removed, trees recycled, to make way for Valentine's cards, red hearts and roses, along with Easter eggs and chocolate rabbits.