In 1981 the Liberal Democrat peer (and practising Buddhist) Lord Avebury let the cat out of the bag, telling a conference on alcoholism that Winston Churchill had been as pissed as a newt for much of World War II. The Churchill industry was outraged. The Great Bulldog's grandson Young Winston harrumphed that it was a "vile and malicious allegation against a man who cannot answer back".

While predictable, this response was preposterous on a number of grounds, not the least of which was that Churchill himself made no secret of his devotion to booze.

"My own rule of life," he once admitted, "prescribed as an absolute sacred rite the drinking of alcohol before, after, and if need be, during all meals and in the intervals between them."

As the writer Auberon Waugh pointed out, it wasn't "a bad advertisement for [Churchill] so much as a good advertisement for drunkenness". Likewise the news that the Australian rugby league player Andrew "Joey" Johns, widely regarded as the best player of his generation, if not of all time, was a habitual user of recreational drugs is on the face of it a powerful advertisement for those banned substances.

The champagne house Pol Roger still gets enormous mileage from having been Churchill's favourite brand. Perhaps at this very moment an Ecstasy lab is planning a marketing push on the theme of being Joey's manufacturer of choice.

But when you think about it, why would they bother? Recreational drugs sell themselves. That's why it's such a profitable business: no advertising, no taxes, and black market prices. On his TV show this week broadcaster Murray Deaker tackled the Johns affair with retired cop-turned-media personality Graham Bell.

In the course of a discussion that veered dizzyingly from inanity - one half expected to be warned about the dangers of strange toilet seats - to insight, they mused on how much better Johns would have been if he hadn't used drugs.

Better than the best? Given what we know, one could persuasively argue that if it hadn't been for the crutch and release drugs provided, he would have been a lesser player.

And here we come to the crux of the matter and the real reason Johns' self-outing is so unwelcome. It demonstrates that, contrary to 40-odd years of anti-drug propaganda, it's possible to be a regular user - if not actually dependent - and continue not merely to function but to surpass one's drug-free colleagues and rivals and achieve great things.

This isn't to endorse Johns' behaviour, particularly the self-destructive component, or advocate the use of recreational drugs, but simply to face facts. The tendency to make policy on the basis of wishful thinking and old wives' tales as opposed to dispassionate analysis has helped get us to the point where recreational drug use is pervasive, entrenched, and criminalised.