We are sitting in the car park at Tesco Stirling.

Mum and I. Saturday evening. Dark outside. We've just been in Bridge of Allan for a late lunch. Tomorrow we're taking her to the circus in Edinburgh [1]. But right now we're killing time on this pre-Christmas visit. J and the kids are inside picking up bits and pieces [2]. Here in the car we're recalling when J and I lived round the corner. I can't say I remember shopping in this Tesco though I must have many times, but over there is the hairdressers - Torpedo by name - where I used to get my hair cut. By J's sister's mate. I doubt she still works there. That was more than 20 years ago, after all. Pity. That was probably the only time in my life I had a hairstyle worthy of the name.

We talk about Stirling and the past then lapse into companionable silence. The radio is on low, but not low enough for my mum not to hear. Radio 2. Dermot O'Leary. Dermot is talking to Elbow's Guy Garvey. J hates Elbow but she's not here so I can listen. Not that I am really listening. I'm just registering the voices, their familiar soothe and balm.

At the end of their conversation Dermot asks Guy for his favourite Christmas song. He chooses Fairy Tale of New York by the Pogues. And so Shane MacGowan starts to sing.

"It was Christmas Eve, babe/ in the drunk tank ..." A moment later my mum joins in with him. "I turned my face away and dreamed about you."

We're not a family of singers. With good reason. Frankly, none of us is even a match for Shane MacGowan. Still, my mum never let that stop her. I grew up listening to her sing along to the radio [3]. The rest of us, though, kept our mouths wisely shut.

The first time I spent Christmas at J's it was a culture shock. They all got roaringly drunk and started singing. Loudly and at length. I can still see J's dad, eyes closed, face screwed up, encouraging J to sing another chorus of Leaving on a Jet Plane.

Back in the present my mum is still singing along to the Pogues. "And the boys of the NYPD choir are singing Galway Bay ..."

And just for a moment I'm thinking of all the ghosts swirling around inside my little Hyundai right now. J's dad, my dad, Kirsty MacColl even.

It's nearly Christmas and my head is full of the season's sadness. And it's soon obvious what I must do. So I do. I join in.

[1] Scotch and soda at St Andrew's Square. Acrobats, nudity and a band. Top night out.

[2] Cider, it turns out.

[3] Jimmy Savile's Old Record Club. But we don't talk about that.