"It's not a virus, it's a bug," I said. "I have got a real bug inside my computer."
Strangely, he didn't believe me. I told him how, on a dark muggy day in Suffolk, a plague of tiny thunderflies had appeared in the room where I was working.
They had been everywhere - on my desk, on the window, even on the screen of my lovely new Toshiba laptop. I had gently wiped the surface. One bug remained, wandering across the restful blue sky favoured by Toshiba for its desktop mode. There was no doubt about it; the bug was behind the screen. The next day, there it was again, moving north. When it finally passed away, the bug became an angry dot on the top right of my computer screen.
It wasn't possible, according to Simon. Nothing could survive the electric current carried behind the screen. He suggested that I spoke to Toshiba.
It took quite some time to get through, during which the Toshiba switchboard comforted me with a soundtrack of middle-of-the-road classics that included, rather appropriately I thought, kd lang's "Constant Craving".
"I've got a bug in my computer. It got in through the side, went walkabout for a while, then died."
"Yes. I rather like nature, as it happens. I just don't want it inside my laptop."
"I'm not an alcoholic."
"And where exactly were you working?"
"In Suffolk. Presumably one is allowed to use a Toshiba outside London."
Ms Toshiba assured me that I was, but also that it was quite impossible for a bug to get behind the screen - unless, she added disapprovingly, the machine had been tampered with. I explained that, due to my deep respect for, and fear of, anything technical, I was not one of life's tamperers.
The next day, as Jonathan from Mastercare was telling me that, if the seal for the screen really were faulty then the water that was behind it would have leaked, something very exciting happened.
"There is another one!" I shouted. "This time on the left-hand side of the screen. A second bug!"
I noticed that Jonathan had become strangely quiet. "And I'm not an alcoholic," I said.
Jonathan admitted that there was a lot of interest in my machine at Mastercare. Nobody had heard of anything like this before. I felt obscurely proud, like a man with an interesting disease.
By now, my bugs played an mportant part in life. Friends rang to enquire as to their welfare. I told them how the second bug, Harry, had looked as if he was going to exit stage left but, with a perverse, heroic defiance, had turned, headed for the centre of the screen and expired. When the delivery man came to collect the computer, I showed him my bugs. He was terribly interested.
Two days later, Debbie from Mastercare rang with the news that the fault was covered by the guarantee. Faulty pixels, it was.
"Do pixels move about?" I asked. "Are they the same shape as a thunderfly? Do they live for a day, then die?"
Debbie passed me over to Peter, the engineer. Like all the Mastercare staff, he was polite and kind - but there was no doubt in his mind. It was true that pixels did none of the things I mentioned but sometimes, you know, your eyes played tricks on you.
"You're saying that for three days I've been imagining bugs behind my screen."
A sympathetic tone had entered Peter's voice. "I know that it might sound a bit rude," he replied gently, "but yeah."
So it's come to this. Either the staff at Mastercare and Toshiba are so absorbed in their technology that they cannot conceive of a small representative of the real, natural world disrupting it. Or Peter is right, and I'm as deluded as any UFO-crazed paranoiac.
"What was the first symptom?" they'll ask at some future date.
"He saw bugs in his computer."
"Oh dear, so sad."
I find myself considering career options. Others have written "Me and my cancer" or "Me and my divorce" columns; is the world ready for "Me and my dementia"?
It's possible, I suppose, that someone out there has a laptop with bugs inside. If there is, perhaps you could make yourself known. My sanity depends on it.
Miles Kington is on holiday.