It's a rum business when, having previously expressed no interest in sport, I now find I not only have serious things to say about equestrian matters – for example, I think all penalty shoot-outs should definitely involve horses from hereon in – but have come down with that form of Olympic fever known in the medical literature (BMJ, XVI) as Olympic Commentaritis. This is not a deadly condition, but it is massively inconvenient as you can't do even the simplest things without whooping joyously and then exploding with excitement. I first realised I'd caught Olympic Commentaritis the other morning, while putting on my socks. "Come on, come on, come on!" I found myself saying, as the tension mounted.

"Keep the pressure up! You have to believe you can do this. Oh, yes! Marvellous! This has to be full marks!" And it carried on when I saw my neighbour, Sue, putting out her recycling. "Some beautiful movements in that routine," I told her. "A wonderful display!"

"On no," said Sue, "what is it this time?" Olympic Commentaritis, I said, She sympathised, she said, but was glad I had at least recovered from my recent bout of ShadesOfGreyitis when I begged every passer-by to call me "baby girl" and whip my "nooni" before flying me to the south of France on a private jet. That was embarrassing, I confirmed, particularly as I had no takers.

Still, I added, at least I can now whoop and explode with excitement all by myself, and Sue not only nodded sagely at this, but queried: "Is it very catching? Will you breathe in my face?"

My favourite name of the games is that of the young Liverpudlian athlete Katarina Johnson-Thompson. I love saying her name for the sheer joy of feeling it roll off the tongue and, because I wish to carry on saying it, I have decided to rename my dog Katarina Johnson-Thompson.

So, if you should pass my house, you will not only hear me commentating on putting the kettle on – "An awkward little manoeuvre, brilliantly executed!" – but will also hear me saying: "Sit, Katarina Johnson-Thompson". And: "Does Katarina Johnson-Thompson want a belly rub? I bet Katarina Johnson-Thompson does". So far today, if you are interested, Katarina Johnson-Thompson has barked at a bush, chased a squirrel up a tree, drunk from the toilet, and been humped by a massive Golden Retriever called Max. "What a great morning," Katarina Johnson-Thompson would have told Clare Balding, had Katarina Johnson-Thompson been asked.

If you could be a great Olympian, what sport would you choose? I had thought about this but it wasn't until I saw the triathlon that I knew, and immediately called my own brother. "Jon," I said, "if we start training now I'm sure we'll be ready for Rio." He said: "Clear off. I'm in a meeting. Don't bother me again." After that, I slumped at the kitchen table, wept a little, and ate peanut butter straight from the jar. Depression, I think, brought on by realising my Olympic dream was over.

Still, it has not affected Katarina Johnson-Thompson, who is happily dozing on the sofa, as I would be if I'd been shagged before elevenses, or had even attracted one taker. Oh well, I've told myself, I gave it 150 per cent, but just didn't have it on the night. Cripes, look at that! I've got Olympic Loseritis As Told To Sharron Davies now...