I live in Kent and work from home. Most weeks, though, I will be in London two or three times for meetings, tastings and other professional excursions. I bike to High Brooms station, then take the train: a 55-minute rail journey.

So today. The weather in this part of Britain has, for the last two or three days, been unusually pleasant: warm and sunny, breeze-stirred and bright. I may be exaggerating, but it seems to me that these have been almost the first nape-rufflingly pleasant days since the wonderful month of April 2007. Last summer was an extended disappointment; winter was largely dreary, occasionally collapsing into viciousness. Easter 2008 was horrible. But now we are relishing a frenzy of leaf and scent, and a newly opened sea of light.

I arrived at the station about 5 minutes before my train was due (the 10:39). All seemed quiet and calm; I bought a ticket from the counter clerk, and wandered on to the platform. There were a few other people there. I noticed from the indicator panel that my train was delayed. The usual inner sigh … but it was sunny, so I walked further down the platform into the light, to enjoy the warmth. I leant against a post.

That was when I noticed the train on the opposite (down) platform. Nothing unusual about it … except that it hadn’t fully pulled into the station, but had stopped prematurely. Puzzling.

Then some police arrived at the station, and ran onto my platform. They saw the train on the opposite platform, and ran off again, emerging on the other platform (the two are connected by a tunnel beneath the line). I assumed there was a miscreant or a drunk on the train.

Actually, they seemed to be concentrating on the carriage exactly opposite where I was standing, which was strange. I could only see a couple of people inside, none of whom appeared notably drunk or disorderly. Indeed they looked calm, sedate, elderly. Moreover the doors weren’t open, and the police didn’t shoulder them open and hurry inside.

I heard someone say ‘the current’s off’. (These lines are electrified via a third, electric rail rather than overhead power lines.)

Then an ambulance arrived. Two ambulances. Paramedics joined the police.

And that was when I realised what was going on. I looked down to the track itself, and saw a body underneath the carriage I had been looking at, no more than six or seven feet away from me. A young man in his twenties, at a guess, just lying there, very still, on his back, a little blood on his head.

I turned away, paced away, my heart sinking, feeling the great weight of human distress concentrated in this place at this time: a pyramid above, and a pyramid below, and the young man the sudden crux.

A helicopter was hovering overhead by now, and fire engines were pulling up, and we were all asked to leave the station, and a young policeman recorded our names and addresses, longhand, in a police notebook. A grey-haired photographer was wearily making his way up the sunlit road, clutching his camera, as I walked away from the station.

The young man has been with me all day, quietly, necessarily inexplicably, and I am wondering what I can do … not to help, since I suspect he was beyond help, but with this memory of this moment. Treasure those one loves, of course; never fail to show love when love is felt; and try to love as widely, and as unconditionally, and as unpossessively as one can.