SORRY for bringing this up in polite company, but when you’ve gotta do it, you’ve gotta do it.

When this column began, more than 10 years ago, the plan was for it to be about life in my forties, but here I am now, writing from the wrong side of 50.

While I am inevitably going to talk about the kids flying the nest, getting too old to play football and worrying about developing an appetite for wearing cardigans, for years I’ve been skating around the subject that is really on the minds of most people of my age, but which hardly mattered previously.

How can I put this delicately?

I’m afraid it’s about answering a call of nature, spending a penny, taking a Jimmy Riddle, seeing a man about a dog, taking a leak, powdering your nose or – if you must use the one I particularly dislike – taking a comfort break.

There is no getting away from the fact that, when you get to my age, your enjoyment of everyday activities, and especially of days out, is mostly coloured by the proximity of the nearest toilets.

And if you want to walk to the pub, you have to make sure you get your routine off to a T. Or maybe a P.

Whereas, as a young man, I could sink a few pints of beer and then walk three miles home without even thinking about needing to turn my bike round (so to speak), now it needs careful timing to avoid disaster.

Not that this is just a male thing. I am obviously not going to go into details, but let’s just say I have it on good authority that there are similar issues, down at the Ladies’ Water Company.

It wouldn’t be so bad if it only played havoc with your social life.

What I hadn’t banked on, all those years ago, was how much it was going to screw up my body clock, on account of you get to see what the bathroom looks like at all hours of the night.

In the first 40 years of my life, I don’t think I was woken up at any unearthly hour once, but now my sleep is broken every night.

Quite apart from the physical stresses this puts you under, there is also a psychological aspect, which in some ways is the most troubling, and this is especially relevant on the long walk home from the pub at the weekend, on those nights when you forget to visit the gents before leaving. About half way home the urge begins, and by the time three quarters of the journey has gone, a feeling of utter desperation has set in.

Every inch becomes a yard, and every yard a mile as all other thoughts are erased from your mind.

And the nearer you get to home, the worse it gets — not just because you are more desperate, but because something bizarre happens: I start to anticipate relief too far from the finishing line.

So I find myself turning the corner of our street and marching down it, with the already key already out, before breaking into a trot and then Usain Bolting the last hundred metres.

All this is not because of any medical condition, just age — and I believe it is coming to everybody.

Bits of me that once seemed to be made of cast iron are now, slowly but surely, on the blink, and the worst thing about it is you can be under no illusions that, once you reach these stages, none of them are ever going to get better again.

And if that doesn't pee you off, nothing will.