Aged 8 my ambition was to ride for Great Britain at the Olympics, clearing the last fence with seconds to go and bringing home gold to the screaming crowd. It never quite happened, but when I received tickets for the Cross Country at the London Olympics it was like Christmas had come again.

I decided that if I wasn’t in the GB team with Zara, William, Pippa, Mary and Tina then I would do the next best thing to support them – I would go to the X Country in full riding gear. Genius and hilarious at the same I time I thought. Surely many others will be doing the same? As it turned out, apparently not.

The weather has reverted to its previous sulky state. Practically the moment Boris handed over the flag, it started raining again, as if the very sky was mourning. I went up to the horse this morning through hills swathed in cloud. You just drive into the cloud, and stay there; it’s quite disconcerting.

And yet, I keep getting happy little flashes of the last two weeks. They are mostly undifferentiated ones of ordinary people smiling and whooping, of crowds going wild with delirium and waving their flags, of walls of sound. (My niece’s husband worked as a technician in the Excel centre, and reported that during the boxing he clocked the crowd noise at the same number of decibels as a Formula One racing car. ‘I think it’s actually illegal,’ he said. ‘I’m surprised health and safety didn’t have something to say.)

I remember the ecstatic rowers and the weeping cyclists and Wiggo and his sideburns and the way his fingers caressed the handlebars of his bike as if he were playing a Bach suite. I remember the horses, jumping and dancing and running their hearts out. I remember the amazed athletes, who never thought they would get near a medal, and the crushed ones, who wanted the gold so much that silver was no consolation. I remember one little boy, caught on camera by the BBC, right at the beginning, saying: ‘It’s like being in Wonderland.’

Now it seems I have turned into the most monomaniac of one-trick ponies. But the British and their equines really have done something remarkable. On Monday, a fifty-something gentleman with a replacement shoulder, an artificial hip, a broken neck, and goodness knows what else, jumped clear round after clear round over enormous oxers and terrifying uprights. It was not just Nick Skelton who excelled, although I do love seeing the old fellas have their day in the sun; it was not just his three bold team-mates. It was the horses as well.

It’s easy to forget the pressure on the horses, who are, after all, flight animals. They come into a strange arena, filled with ecstatic cheering crowds, waving flags, taking pictures. All the while, announcers are calling through microphones and helicopters suddenly circle overhead. It’s almost a perfect storm of everything the horse is bred not to like. It does not necessarily think: all those lovely Britons are cheering for me. (Although some horses are born performers and rise to a crowd.) It is more likely to think: damn, mountain lions at three o’clock.

My mare doing her own little dressage test, in honour of her compadres

I’ve decided that I shall officially get excited about the Olympics. There is, of course, a huge amount to grumble about. The car lanes stuffed with sponsors and bogus VIPs, the ghastly creaking corporate bandwagon, the idiocy of having a great sporting event sponsored by crappy hamburgers and sugary drinks, the security fiasco: all make one’s heart sink into one’s boots. But it would be sad to allow all that to obscure the human side.

This morning, Alice Plunkett, whom I watch all winter as she presents Channel Four Racing, tweeted that the lovely Lionheart had set off for Greenwich. He is the horse of her husband, the great eventer William Fox-Pitt. As all the noise is of the famous sprinters, the swimming hopes and the cycling heroes, the horse side of the British contingent is often overlooked. Eventing is the most minority of sports, after all. I always love the Olympic three day event, but now that I have a horse of my own, I feel it even more keenly.

It is one of the most challenging disciplines of any sport. It is, essentially, a triathlon with horses. First, they must do the delicate, controlled, precise test that is dressage. Then, they must go flat out across country, over terrifying fixed obstacles, with huge drops, shining water features, and any other kinds of novelty that the course builders may dream up. This requires strength, stamina, courage and accuracy. It’s about as far away from dressage as you can imagine. Then, they must go into the show-jumping ring, and tackle a completely different kind of fence, with fragile poles that can fall at the flick of a hoof.