Today I went to Postman’s Park. There was a white tree blooming in the centre of it. Dira knew where I was, she began to play Damien Rice – Volcano, which I don’t like, so I flicked around to the right song, which was the Blower’s Daughter. I walked under the white tree, towards the Memorial of Heroic Sacrifices – a wall of plaques to commemorate those who died trying to save other people. Sometimes people they knew; mostly complete strangers.

The film Closer opens with the Blower’s Daughter playing as Natalie Portman and Jude Law walk towards each other in slow motion through a crowd. She catches his eye; he smiles. Her hair’s red. So is the traffic light: he stops; she keeps walking. The camera stays on his expression as he watches her get run over by a taxicab.

In the street, Jude Law bends over Natalie Portman. She opens her eyes and says: “Hello, stranger.” After he’s taken her to hospital to get her leg fixed, they go to Postman’s Park. He asks her name; she tells him it’s Alice Ayres.

I walked down the memorial walk listening to the Blower’s Daughter and reading the plaques; by the end of it I had started to cry. I don’t know why. Maybe it was because the place was so beautiful. Maybe it was because the plaques were so sad. Maybe it was because I felt alone in London; maybe it was because I realised that, faced with the memory of these people who had given their lives for strangers, my loneliness was utterly insignificant.

Here’s to strangers. Maybe someday, one of them will save you.