Christmas is a time for traditions. If yours is a nativity pizza, who am I to judge? | Jay Rayner

We may want tradition to be mystical and ancient but in truth it's exactly what we say it is - be that Baileys, beef rendang or turkey and all the trimmings

In early November, the nice woman at the checkout of my local Sainsbury's pointed out a nearby stack of Baileys. Just 10 a bottle," she said, with a cheery wink. Proper bargain." I smiled thinly. She clearly had no idea what sort of a person I am. Baileys? In November? Don't be so disgusting. Baileys is for Christmas. The annual bottle comes into my house on 20 December and not a day earlier. Because Christmas is a time for traditions, and the pre-Christmas bottle of Baileys is one of mine. I am stone-cold certain it is exactly what the Baby Jesus would have wanted. Why? Because I say so.

The word tradition" is solid and reassuring; the things that word refers to are often rather less so. To mix our cultural references, the point is best made by Tevye in the opening song to Fiddler on the Roof. You may ask, how did this tradition start?" he says, having introduced the audience to his fellow villagers. I'll tell you - I don't know. But it's a tradition." Indeed it is.