When we heard recently that Syd Barrett, the reclusive former member of Pink Floyd, had died at his semi-detached home in Cambridge, many things intrigued those who remember his music. Why did he choose to live alone? Why did he shun the money? What was he doing in such a small house? But for me only one thing was truly shocking. He had died at the age of just 60. Now I know that if you’re 17 years old, 60 is as far away as the moons of Jupiter. But for me, living in the accelerated space-time continuum of middle age, 60 is tomorrow morning.

Scientists say the smallest measurement of time is a femtosecond. A million billionth of a second. But when you’re older than 45, the smallest measurement of time, actually, is one year. And if I live to 60, I only have 14 left. That’s 5,000 days. And that’s only 120,000 hours.

I think often about how I shall die and when. I find myself looking at really old people and wondering what it must feel like; to know that you’ve reached a point where your life expectancy is measurable in minutes. Why aren’t they all running around waving their arms in the air panicking; because they must surely know that soon, everything that they hold dear — everything — will soon be replaced by the utter blackness of eternity? I get a lot of practice at thinking these things because in my life, every lump, bump, cough, ache and pain is the onset of some terrible killer disease. I catch ebola three times a week, and back in June, having discovered a nodule of something unpleasant near my left elbow, became fairly convinced I’d become the first person in human history to catch arm cancer. A few days earlier, I had managed — just — to shake off a nasty bout of ear TB.

Of course, most of my ailments are designed so that I can lie on a sofa while my wife brings me poached eggs on toast. I’ve never really thought I had cancer, so I’ve never really known what it must be like to stare the Grim Reaper in the face and know that time’s up. Last weekend, however, all that changed . . .

Now I want to make it absolutely plain before I go any further that I do not find bottoms or anything which comes out of them even remotely funny. I am not seven years old and I am not German. But there’s no way of saying what I’m about to say without being lavatorial. I’m sorry for that.

What happened, you see, is that after my usual morning’s number twos, I noticed that the water in the bowl was red. Which meant of course that I had, without feeling any pain, passed a small amount of blood. Plainly, I had prostate cancer.

I am aware of this disease. I know that it is the most common form of cancer among men and it is likely to strike when the victim nears 50. I even know what colour wristband you should wear to show you support it (blue).

I knew too that I needed, urgently, to check mine out and so, armed with nothing but a well-oiled finger, went ahead and violated what for 46 years has been a strictly enforced one-way street.

I shall spare you the pain and the humiliation of this hideous potholing expedition, but I feel duty-bound to explain that once I was in there, ferreting about, I realised that I didn’t know what a prostate is, or what it feels like or where it is exactly.

It’s much the same story with the endless requests we get from doctors to check out our testicles for early signs of cancer. I’m sure this is jolly good fun, but unless you tell us what we’re looking for, how will we know when we’ve found it? And skin cancer too. How can you tell the difference between a mole and a melanoma? I’m sure it’s possible if you’ve spent seven years studying medicine, but what if you’re a fork-lift truck driver? I’ve examined thousands of photographs of malignant skin growths and they all look like every freckle on my body.

After a bit of research on the internet I discovered that a prostate is about the size of a walnut, that it’s used to make fluid in which sperm is transported and that it lives “near” the rectum.

And eventually I did discover something in my bottom that fitted the description. But with knowledge gleaned solely from the BBC website — which almost certainly will blame the rise in popularity for prostate cancer on either the Israelis or global warming — and with nothing to hand except a soapy index finger, I’m afraid I wasn’t able to say whether whatever I’d found had cancer or was in rude good health.

The only evidence I had was the blood, and that really was enough.

I was finished. I wasn’t even going to last as long as Syd Barrett.

I heard the other day that 80% of patients, when told by a doctor that their tests for cancer had been positive, make a joke of some sort. Wearily, I went downstairs wondering what mine might be. Something about getting the spare room painted perhaps . . .

And there in the kitchen was my wife. “Morning,” she said cheerily. “Have you been to the loo yet, because that beetroot we’ve been eating doesn’t half make it red.”

I’ve never felt so happy in all my life.

Times Recommends

• We have kit and leadership. Let’s go
• Behind the scenes at the biggest deal
• Conferences — what a waste of money