You are reading a columnist at the peak of his mental powers. These last decades have been an arduous ascent but lately my brain has reached its optimal cruising altitude. It doesn’t get better than this.

Be assured as you read on of the vastness of my accumulated knowledge and that my emotional maturity is operating at its absolute zenith.

What we’re talking about here is a guy – me – reigning supreme in the golden age of his cerebrum.

Think twice before taking me on in mind games. I am between 55 and 60 years old and therefore at the ‘apex of psychological readiness’. Things could get messy for you.

I have a team of scientists to thank for this bout of intellectual self-confidence. They have found that, contrary to popular belief, our brains provide their most estimable service to us much later in life than we imagined.

It comes at the very juncture of advanced middle-age from which I am addressing you right now – here on the summit, watching you younger folk toiling up towards me and you older ones trudging your way back down.

It may be true, says the newly published research, that ‘fluid intelligence’ peaks around the age of 20 and that it’s a slippery slope from there on in. Sure, brain volume begins its decline in the early 30s, which means my grey matter has been shrinking for a quarter of a century.

But, by my age, what I have lost in processing power and hardware degradation is ‘outweighed’ by what I have gained in life experience, emotional stability, decision making ability, financial literacy, vocabulary …

It’s all there in the science journal Intelligence. In the profit and loss accounts of the handful of decades our brains are in business, the healthiest margins are to be found in your late 50s.

I would love to tell you this research chimed exactly with my own data on the performance in the engine room between my ears, that I was smugly conscious of the maximum throughput going on in these precious years of prime efficiency.

It would be a joy to swell with pride – as the captain of an Edwardian ocean liner might – at the precision pumping of the piston galleries, the finely tuned machinery humming below deck.

But you will likely have guessed the vessel to which I allude. What is going on at this stage in the journey is beginning to feel distinctly post-iceberg.

You barely notice it at first. So your brain won’t give you the name of a politician you have spoken to many times before. That is understandable. You have spoken to a lot of politicians. They are highly forgettable people, many of them. A degree of corruption in your files is to be expected.

So, mid-sentence, you realise you must recalibrate because a key word you intend to use in half a second’s time has deserted you in your hour of need. You’re probably just tired.

No, you’re taking on water.

I have been learning Spanish for five years in the hope of one day conducting intelligent conversations with friends in Mallorca.

I encountered one last week – Antonio – who wanted to show me his splendid garden. I gazed dumbly at his vibrant bougainvillea, unable to recall a single word of vocabulary appropriate to describe it.

He looked at me expectantly.

What to do as the silence lengthened? Did I really have to stand there and go into Google Translate on my phone to look up the Spanish for a word as basic as ‘beautiful’? ‘Magnifico!’ I blurted out finally, finding inspiration from the Italian section of the Queen song Bohemian Rhapsody where none would come from my years of Spanish study.

Was ‘magnifico’ even a word in Spanish? Antonio smiled as if it might be.

Or perhaps he was smiling at age catching up with me – noticing the water levels rising on my cognitive function.

I seem to notice it daily. I move from room to room and arrive at my destination unsure of what I came for.

I go back to the original room and then remember what it was, but set off to a completely different room to fetch it.

The other day I was telling an acquaintance how pleased I was to have given Glasgow’s Southside a chance after many years of living in the West End. Ah, said he, a fellow Southsider, what street did I live in? I went blank.

At my age, this ‘apex of psychological readiness’, people ask such tough questions.

Up here on the mountain top where I am supposed to be looking down on all you unfortunates who are the wrong age to be firing on all mental cylinders, the truth is that trust in the old internal hardware is evaporating. I am outsourcing increasing amounts of labour to processors I trust more.

I have entirely given up on pitting my failing wits against my phone. These days I don’t even attempt to use logic or trial and error to complete tasks on it. I go straight to my new best friend, AI mode on Google, and ask it for an idiot’s guide.

No, you’ll have to explain it more simply, I tell it after the first attempt goes awry. I am a bigger idiot than that. I am not so idiotic as to ignore the perils of forgetfulness.

Only once – okay, twice – do you find yourself 20 miles into a journey for a weekend away from home and decide to turn the car around because you can’t remember switching off the gas ring you had the breakfast frying pan on. Or you have no memory of locking the door, or you might have left the windows wide open.

No, you double, triple and quadruple check all these things, then you realise you’ve set off without your phone.

I date the iceberg strike back a good seven or eight years, and I’ve been manning the pumps for almost as long. We’re going down into the drink, certainly, but no reason to flee the banquet hall just yet. Play on, string quartet.

While no vessel may be truly unsinkable, there are ways and means of arresting the decline – even of quite enjoying the doomed bail-out operation.

Half an hour or so a day solving puzzles on the Mail+ app can leave me quite buoyant, especially when I can compare my performance against other readers doing the same brainteasers that day.

On a good day I’ll get the quick crossword done in under four minutes.

Through necessity or boredom (I’m never quite sure), I also drift into TV quiz shows and derive some small satisfaction from the fact my brain is in nowhere near as much trouble as those of most of the celebrities on The Weakest Link.

Then there is the aerobic chess of table tennis – a thrice weekly pursuit for me which health experts everywhere insist is the best mental and physical work-out for the fading 50-something.

Not so much on the mountain summit, then, but inching below the water line – with wisdom and humour, I hope.

Enough, at least, to take those scientific studies with a pinch of salt.

j.brocklebank@dailymail.co.uk