A breakfast meeting at Claridges was embarrassing in a white fox fur wrap. All the Russians and Americans were in jeans and my date was in a track suit and just out of the shower. She clearly has breakfast there every day and she went round the room slapping the odd solitary general on the back before she sat down. The waiter put her usual in front of her before even giving me the menu. Anyway, the reason for my looking so absurd was that I was on my way to a wedding.

‘You’re not the bride are you?’ the cab driver joked as I got in, my hair sticking to my lip gloss in the breeze. ‘No. But I am an ex-girlfriend of the groom and if I pile in at ‘just cause and impediment’ it will be excruciating.’

It was close, and we went up on to the curb near Trafalgar Square to get past a bus. I was the last guest into the church and I flumped down next to my husband in the back row still gasping for breath. The doors had already opened on to the bride by the time I took my shades off and, oh Christ, dismantled my phone (it beeps when you switch it off, so you have to take it apart silently as if you have only seconds to save the universe from destruction).

This was my first love getting married. The church was full of people who had been our friends in 1989, who had seen us make fools of ourselves in love and watched the acrimony and carnage which, in fact, went on for years (though they weren’t obliged to watch it all, you understand). We are good friends now, which is quite a feat considering.

I knew I would cry during the vows, just for our youth and our promises, my blue dress with the daisies on it, his cricket whites and all our hope for the big wide future.

He came to my wedding twelve years ago and, at the party afterwards, he came up to me and scowled. ‘You’ve just married somebody else,’ he said. I burst into tears. And not because I wish I’d married him or vice versa (I think we both feel we had a bit of a lucky escape) but because we really thought, for six months more than twenty years ago, that we would be together forever. We read Donne poems to each other (this seems so unlikely now that I wonder if I made it up) and played chess stoned. We lay on a beach in Tunisia and he read out loud from the Anglo-Saxon primer and I read to him from War and Peace. We were going up to Oxford together that September.

The idea of us then and the truth of us now seems to represent that childish hope and promise that eventually came up against reality. Hard. It was bound to, of course, but I remember the feeling of driving around London that summer in his ancient Escort, knowing I was home at last. We thought life couldn’t touch us. But it did.

This was actually my first time at an ex’s wedding (the others didn’t invite me!) and I hadn’t realised how subtly sad it would be (aside from the more obvious joy). I expected to cry at the vows, and at how beautiful the bride looked, partly just because it was a wedding and I always do, but I hadn’t expected to see my life flash before me in the ageing (or, perhaps, ageless) faces of people from then, or to think about all the things that did and didn’t happen, the future we imagined and the future that came, and is now past.

And it’s funny how life turns out. I would love to have known then that I’d be forty, having breakfast with a Hollywood exec in Claridges the morning of the day that X got married.