When the vet had finished giving my horses their annual flu boosters, she reminded me the vaccination regime had changed. For the purpose of competing, horses must be vaccinated for flu every six months, which is something that had passed me by.

What with worrying about human vaccines, I had not noticed this change in the rules for equestrian jabs.

I thought about it for a split second, then decided. ‘Lucky I don’t compete then,’ I told her. Because being a rabid anti-vaxxer, I don’t want my horses pumped more full of vaccine than is absolutely necessary.

And this is precisely the sort of irrational and illogical reaction people have come to expect from someone like me.

I admit it, I’m so anti-vaccine I pay a vet to come out and give my horses a flu jab every year, and I don’t just unquestioningly agree when, after 20 years of this routine, for various horses, with no problems, the vet suddenly informs me that many owners are giving the same jab every six months now.

‘In terms of immunity,’ said the young girl, as she put the used syringes back into the boot of a 4×4 she didn’t look old enough to drive, ‘it obviously doesn’t make any difference.’ (The vets are now so young you have to help them. This one wrote April 2021 beside the vaccine stamp on the horse passport.)

‘I’m sorry, what?’ I asked. ‘Well, obviously, they don’t need vaccinating every six months, it’s just the rules have changed.’

I suppose this rule change will, coincidentally, make everyone involved, from vets to vaccine manufacturers, a nice pile of money, but all the same I said I would ring and make an appointment as usual next year.

She said that was fine, because it didn’t really matter. Just if I wanted to compete, I would have to have more vaccine.

Broadly, in terms of booking them in, it didn’t make any difference if I made it six months, eight months or 12 months. It didn’t sound very precise, is what occurred to me.

I said I would definitely bear that in mind, and I would ring and book my thoroughbred Darcy in for a six-month booster if I suddenly felt the urge to take her to Hickstead. But while saying this, I made a mental note to possibly try even less hard than I already do when I have my jumping lessons.

I’m 50, so I think I’m doing pretty well to still be on a horse, never mind jumping. Once a week, with a trainer who is extremely patient with me, I do little jumps, much littler than Darcy is capable of and would like to do. She hurtles over them way higher than she needs to, and gets very overexcited. Because I’m so scared of smashing my post-menopausal bones to bits by falling off over big jumps, Darcy pretends they’re bigger, in order to have some fun.

The trainer put a metre jump up the other week and asked how I felt about it, then, as I grimaced, he put it down to two foot and gratefully I cantered round in a circle and flew over. The fact that Darcy still jumped a metre in the air didn’t bother me.

But if going to competitions and actually jumping a metre – with the pole in the metre position – means pumping her full of flu vaccine on a six-monthly basis, then I’m less motivated than ever to do it.

What do you expect from an anti-vaxxer? We are all horribly selfish, as you know. We are also somewhat paranoid.

I’m sure all my fully vaccinated friends look very well and are proving to be very strong and resilient, being as free from coughs and colds and Covid as a person with a fortified immune system should be. The fact I don’t particularly notice that is indicative, no doubt, of my problem, my mental block, my belligerence.

The builder boyfriend is the same. He went up to the Waitrose garage for a chicken the other day and came back to report he had just run into two friends of ours who we haven’t seen for ages and he was shocked by how awful they looked.

‘What do you mean?’ I asked. And he started to explain. And I began to worry that he and I are becoming delusional, seeing things that are not there.

I’m sure everyone is absolutely fine and everything is precisely as it should be. Of course, I’m a fool for not having it. And now I’m extending that pig-headedness to deprive my horses of the chance of a twice-yearly flu jab just because the vet admitted that in terms of their health it was enough to have them done annually.