Sir Alex Ferguson has given his strongest hint yet that he wants to continue managing Manchester United past his 70th birthday. It had been widely assumed that the 66-year-old Govan Battler would disappear into the sunset at the end of next season to spend more time with his hairdryer, leaving the reins, perhaps, to one of the many former United players who have followed their mentor into management. But his comments on the eve of Sunday’s 1-0 away win against Manchester City suggest otherwise. “Why would I pack it in at the moment?” he said.

“I don’t ever think about it any more — it’s all out of my mind. I am not even going to put myself into that situation where I am thinking, ‘Should I this year, should I next year?’ ”

Ferguson’s intervention evoked the infamous remarks of Margaret Thatcher, who vowed to go “on and on” in the late 1980s, before being stabbed in the back by backbenchers and Cabinet ministers, who she would later describe as “lily-livered cowards”. It would be a shame if Ferguson went the same way, spending the rest of his life harbouring bitterness towards his assassins — whether they be the board or the fans. But this is what awaits him unless he steps down of his own accord, because nothing lasts for ever — except perhaps his grudge against the BBC.

There is something deeply fascinating about Ferguson’s unwillingness to exit the stage; his visceral desire to test himself yet again; to prove his ability to outwit, out-think and outmanoeuvre yet another generation of young upstarts. His stance is not unique, of course, but common to many of the sportsmen and women, coaches and managers who have reached that elusive destination called greatness. We love to watch them, to write about them, to talk about them. My colleague Simon Barnes calls it the “essence of Redgrave”, a tribute to the insatiability of the rower.

But is this obsessiveness, this inability to move on to pastures new, this relentless and ultimately futile battle to subdue one’s inner demons (inner insecurities?) so very admirable? Is it something you would want for your children or partner? Could you imagine living with someone whose life is defined by such narrow parameters as to be found within the confines of a football pitch?

Is there not, in this strange journey called life, something to be said for diversity, range, art; for new challenges and horizons; for what Denis Healey — that most urbane of 20th-century politicians — called a hinterland?

I ask the question for it leads to something else that has been bugging me for a while. Have you noticed how the sports lobby keeps waffling on about how wonderful it would be if the 2012 Olympics acted as a catalyst for kids getting on to the playing fields — partaking of the joy of sport — and how this will lead to a new flow of talent on to the podium? Sounds marvellous, does it not? But it rests on an almost entirely overlooked contradiction.

For there is nothing in common between sport played on grassy verges and that undertaken in the High Performance Centres that churn out Olympians. One is amateur: the stuff I do on Sunday mornings with my buddy Mike — a couple of sets of tennis, followed by some banter over mushrooms on toast. It is about fun, fitness and a bit of edgy competitiveness, particularly when we play for a few notes. But the other is a rigorously programmed, scientifically monitored, endlessly meticulous quest for gold, intolerant of other interests, insistent on ruthless dedication and demanding of unnatural and — it has to be said — wholly unhealthy levels of devotion.

I would love my kids — if I eventually have them — to play sport, but I would not be at all eager for them to turn pro. Those that do witness often a transformation into Terminators intent on gold to the exclusion of all else — and that is just their parents. I am not saying all top sportsmen are maladjusted, but can it be denied that a worryingly high proportion are? Balance is not a word that you will hear many performance directors using in the build-up to London 2012, except as a term of derision.

Don’t get me wrong: the quest for excellence is a wonderful thing. But is the quest for victory over and over again — when you already have ten titles, two European Cups and five FA Cups — really so admirable? Is it not, on the contrary, rather distorting of human experience? I offer the humble observation that Ferguson would do better to let go sooner rather than later and experience all the rest that life has to offer. He will doubtless disagree, insisting he has sufficient balance — he loves the horses — and castigate the way I live my life. That is his right, and mine.

But let us agree on one thing: it is time to drop the pretence that the institutionalised pathology of professional sport has anything to do with what you and I get up to on the tennis court or football pitch at weekends.