Between various websites and two lashings of Woman's Hour, we learned that by the end of the decade 40 per cent of households will comprise just one person; indeed, if you add to that the many who are single but not alone - dwelling, perhaps, in shared homes with friends or with adult children - you might reasonably conclude that, even within our lifetime, those living in what the BBC delightfully dubbed 'singlehood' could easily number half of us.

It is, therefore, at least as astonishing as it is irritating to hear such a whopping great swathe of the population treated not as the norm, but as deviant. Singlehood, it was made soberingly clear, is a social pathology deserving of sympathy and aid, to which end the corporation's online chat service offered someone from 'Single Again' and someone from 'So You've Been Dumped' [sic], each there 'to give advice on how to be positively single'.

Most of those who participated in the broadcasts, both on the professional panel and on the interminable phone-in, were middle-aged - well, they would be, since the unmarried 31-year-old is merely a 'not yet', still 'optimistic' or 'still waiting for Mr or Ms Right to come along' (ye gods, in 2002?). So we were treated to a well-meaning, middle-aged Jenni Murray asking her contemporaries why they are not married and how on earth they cope.

They mostly sounded, bless them, rather pathetic; put on to a defensive back foot where all that was left to them was justification, there was a lot of muttering about the infinite pleasures of choosing which television channel to watch, while around the nation you could feel the nods and winks that said oh aye, she'd give anything for a chap, she would.

Not one among them, it is sad to report, thought to reverse both the question and, in the process, their defensive position. But people never do. Nobody ever turns to their middle-aged chum and says listen, my friend, rather than have you always asking why I am not married, may I ask: why are you?

To a great many of us, the proliferation of marriages that extend beyond child-rearing years is mystifying. 'It's about la-la-love,' some will stutter if put on the spot, and those, of course, we shall not deny - at least, not when we believe them - since it is evidently true that some couples have constructed a partnership that has strengthened with time and evolved into an enviable companionship.

That said, the 's'obvious, innit?' ingredient of a lasting love as the cement of a lasting relationship is, equally obvious to any observer, absent in a great many - as some of the more honest will acknowledge. So why stay? 'Because I don't wish to die alone,' admitted one frank friend, as we wait to see whether he or his wife wins the race to bore the other to precisely that point.

And what a gruesome spectator sport that is, as we observers recoil from the stink of the decaying marriage; from the catatonic couples who become animated only when the children fleetingly revisit the nest, or from the couples whose rictus smiles and lavish endearments do nothing to mask the tension of the constant bickering - all of them smothered in a misery of their own making, few of them prepared to do a darned thing about it.

None of this, you ache to whisper to them, was meant to be. Nor yet is it approved by time or tradition; the poor of old either kept or cast out - usually the former - their widowed, their orphaned and their ungainly, thus diluting the loneliness of the marital couple, while the extremely wealthy of old enjoyed largely separate lives, right up the social scale to the point of maintaining separate courts.

It was only the capacious appetite for a compliantly mobile labour force, during the relatively recent industrial revolution, which decreed that man and woman should pair in isolation, raise fledglings who would eventually fly and then be left alone together - and even then, both he and she should have been about ready to drop dead when the aloneness came.

This extra quarter of a century or so of - what would the BBC call it - doublehood? - is artificially engineered, and in all too many obvious cases, a needless purgatory. Look at you, you sometimes yearn to challenge your listless friends: you are crushed by tedium and repetition, you are without passion or stimulus and you cannot hear that joke one more time without choking. You have earned the money and the independence to choose each companion for the mood of the moment; to enjoy sex with one - or more - of them; to reap the freedoms that follow the parenting years. Come on: it's payback time.