There was a time when old people knew their place. You could rely on someone aged 50 or over to accept that, barring any major scientific breakthroughs, their life was essentially over.o After all, you can't really have sex once you are 50-plus because bodies, unless pampered over for a lifetime, just lose their elasticity and sag.

And if you are still sport enough to try and pull something younger, teenagers are just going to shout 'Mail Order Bride' or 'Toyboy' as you limp down the street.

But I've noticed that in Oxford, something of a revolution is now taking place.

People who once would easily have been considered over the hill (that's men in beige M&S outfits and women in anything that still fits) are now driving around, brazen as you like, in sports cars.

Now immutable as the laws of physics are, so too are the rules which govern ownership of sleek, cougar-like roadsters. And the first rule of this science states quite clearly: 'Pre-retirement individuals attempting to reclaim lost youth risk social and emotional alienation'.

There, I've said it. It's in black-and-white, a scientific fact, and yet for some bizarre reason, I've recently spotted large numbers of these sad and pitiful types.

Not content with drooling in their rest homes or wondering why their kids don't call, they're out and about, larger than life, naively taking on the march of time, and here's a surprise, losing. I don't know why they think it'll make a difference, because it never does.

In Abingdon, I suffered a bout of nausea when I noticed a woman in her early fifties trying to squeeze out of a Mazda MX-5. I was struck by the incongruity of the scene; the car, albeit a hairdresser's favourite, with all the right curves and sheen, bought to supposedly reflect the youth, vigour and sexual stamina of its owner.

Tragically, what she didn't realise (or was deliberately blind to) was that ownership of this red, hot pepper only heightened the difference between it — and her.

She had all the grace of a Cane Toad, and it had all the grace of a hooker's stockinged calf...

Likewise, at The Plain in Oxford, I spotted a balding (as opposed to sexily shaved) wannabe pensioner, revving his Porsche Carrera, roof down, with the clear conviction that what surrounded his bucket-seat posture was an in-yer-face badge of sexual prowess.

Or put another way, in front of a car showroom mirror, he'd seen a maturely macho success story; to everyone else, however, he just looked like a sad old man.

Of course, I blame property prices; after all, there was a time when only the rich could afford such toys. But with property values having made many of us wealthy for doing little more than staying put, the opportunity for civil servants and retired teachers to find such racy models within their financial reach has increased.

And sadly, while you may be able to turn the clock back on your motor, the same isn't true for yourself. Naturally, some older people drive Aston Martins and Ferraris, but they are spared our ridicule by the fact that in their youth they were successful. And because successful people tend to be inventive, creative, smart and charming, they would, with or without their cars, prove attractive.

But if you can only afford the Lotus because a recently deceased relative named you in their will, get real — a Lotus in a scrapyard is still a Lotus; a retired payroll clerk is... hell, just that.