It's late afternoon, the end of a summer Sunday and the train is full. We sit quietly, each a little tired, each perhaps thinking about the film we've just seen.
I look out of the window, watching the jumble of office blocks give way to the backs of houses, seeing the concrete yards become gardens that gradually get longer and greener. I wonder about all the people who work in those offices, live in those houses and play in those gardens. I think about the girl from the film. So many different lives; chances taken and missed, opportunities grasped and squandered, promises made, words spoken and regretted.
A woman sits opposite me, leaning against the window. Her arm is loosely draped around the daughter who's half sitting, half lying across her mother's lap . Next to the girl is a young boy, maybe six years old. He sits cross-legged, tidy, taking up hardly any space. I imagine him sitting on the carpet at school, listening closely as his teacher reads a story, trying hard not to miss a word. He's holding a small bag of sweets, slowly licking and nibbling at each one, as though trying to make them last the whole journey home.
Across the aisle are three teenage boys, each wearing the football strip that betrays how they've spent their afternoon. They're talking at each other, across each other. One bites into a burger, another shovels in a fistful of thin chips. The third takes his shoes off, and rests his bare feet on the empty seat opposite. I try not to think about the trace of adolescent sweat they'll leave behind.
"I want Mummy to sit in the middle" says the six-year-old, pulling my attention back to our side of the train carriage. "Then I can have a cuddle."
"You can have a cuddle when we get home" his mum offers. "And I'll read you a story."
She looks across at me and smiles, and I wonder if she realises how lucky she is. I glance again at the football fans, their shirts tell me they support the same team as my sons. I try to remember the last time I sat on a train with my boys, or walked along the street holding a small hand in mine.
And I want to tell her to cuddle him now. I want her to know that all too soon, her tidy little boy will be six foot tall and too embarrassed to hug. I want to urge her not to miss her chances, but I don't. Instead, I look at the boy, who gives me a huge grin, and then I smile right back.