All jolly good things - tick, v.g., keep it up. But then I watched the heart-stirring finale of the Channel 4 show Musicality, and my thoughts took a different turn.

Yes, we have to encourage talent, cure timidity and self-denigration and frown on timewasting. Yes, we should probably encourage children to identify their gifts and aim high, whether in academe or business, professions or performing arts. And yes, we have to equip them psychologically for the possibility of a few failures along the way. The need for talent to be backed up by effort and character is a fact of life.

But watching the amateur contestants in those unusually benign and joyful TV competitions, Operatunity and Musicality, another fact of life has been borne in on me. Face it: some people have great talent but don’t fulfil their “potential” for perfectly good reasons. All of us have to make certain decisions as we go through life, and following our talent is not necessarily the first priority at all times. It has to take its place in the queue of odd imperatives brought on by family and fortune and the circumstances of the age.

Thus it is not the young contenders in these shows who are interesting, but the older ones. Some of them are absolutely stunning, so that for a moment you think “Hang on, why are these people not already professionals?”.

Paraded before us in the auditions there have been stunning basses and tenors who work as salesmen or plumbers, spectacular sopranos who have passed a working life telling dentists’ patients to rinse and spit, and snake-hipped show dancers who sell curtain-rings in John Lewis or ply a sober trade as physiotherapists.

But that’s how it is, isn’t it? In our own lives we have all met potential stage stars who opted for steady day jobs and now happily fritter away their “potential” in church hall shows. We all know artists - in every field - who keep their own work to the evenings and weekends. I have had my eyes tested by a seriously gifted “cellist”, and on my wall hangs a marvellous painting whose artist spent a salaried lifetime in teaching.

Years ago I interviewed a courteous, expert and careful elderly railway line engineer, the old kind who made you feel safe on any rails he had charge of. I asked whether he had always wanted to work on the railways, and he stared and said “No. I trained as a court dressmaker. But the depression came, and I had a family to feed”.

Talent sometimes crops up in the wrong place and the wrong time, and there is little to be done about it. There are people who would have been good doctors, but who came of age at a time when the medical schools were oversubscribed. There are law clerks who set out to be barristers but were beaten back by the costs, the time, and an unexpected child to support.

There are countless women in untaxing or part-time jobs whose personal “potential” has always come second to looking after a family and a higher-earning husband. And there are plenty of people at large who could have made careers in stand-up comedy or sport or dance or journalism or rock music or poetry or orchestras, but made a considered decision not to.

For one reason or another - temperament, circumstances, responsibilities - they decided not to embrace the risk, the early poverty and continuing uncertainty which attend those trades. Others did; some succeed early, others never, and many find themselves at 40 still living in a rented bedsit and glad of any gig that offers itself.

The people who decide not to risk that life do not, as a rule, repine. They know what they chose. Perhaps they use their gift in their spare time, to the general glee of local audiences. Perhaps their poetic and fictional talent goes into jazzing up the company’s annual report or sending brilliantly funny emails. In any case, they have learned to measure success by their own standards and their own satisfaction, not by tawdry yardsticks of money and fame.

But I think that anybody discussing careers with children should bring up the subject of attitudes to risk and the effect of Cyril Connolly’s “enemies of promise” like the pram in the hall. And any university student balancing an exhilarating hobby with essay crises should be aware that the whole of life is a bit like that: a balancing act. We should accept, with a regretful shake of the head, that half-buried talent is not always due to unfairness, and is not always a tragedy.