Thomas Sutcliffe: No need to be a dope over a youthful error

I think David Cameron told a lie the other day. I can't be sure you understand - and my uncertainty is compounded by the ambiguous nature of the utterance in question. So let me state now, should his lawyers give a damn one way or the other, that I am happy to accept that Mr Cameron's fidelity to the truth is unspotted. And yet still the suspicion sidles back, like a dog that's smelled a hidden treat. Shall we call it a fib instead? An understandable economy with the verité? A modest sacrifice to the god Humbug?

What I have in mind is his statement that he had done things in the past which he "should not have done and that I regret" - a remark which we were invited to take as a tacit confirmation that he had smoked cannabis while at Eton. And in one sense, of course, there's no question that he probably does regret this.

It's hardly career-threatening - however shocked the zero-tolerance junkies pretend to be - but it is a minor political distraction that he would probably prefer to do without. I don't think Mr Cameron or his advisors wanted us to construe this statement in that way though. It wasn't supposed to be a paraphrase for: "Damn, I knew that would come out one day. Hope it doesn't dish my chances".

What Mr Cameron wanted to suggest was mature contrition - that, in terms of conscience, this had always been a stone in his shoe, one of those memories that the mind tries to keep its weight off, but which occasionally digs in painfully. And I just don't believe that's true.

I'm sure he regretted his misdemeanour quite a lot when writing out Latin verses as punishment, and a little more when he realised he'd have to tell his parents. But I imagine his appointment as a Head of House not long after put paid to the immediate regrets about lasting consequences and I doubt he's ever regretted what he did as a personal moral lapse.

It would be rather unhealthy if he had. While there are things that are worthy of lasting regret - hurting people, failing to seize opportunities - a youthful misadventure like smoking a bit of dope isn't one of them.

Senator Barack Obama has been obliged to go through the same pantomime of admonitory remorse, after confessing in his memoirs that he'd smoked pot and even taken "a little blow". Initially, he handled this with some flair: "When I was a kid, I inhaled," he told one interviewer. "That was the point". As a rebuke to President Clinton's self-serving prevarication on this matter I thought this had some style. Who would want to vote for a man too dumb to suck?

Unfortunately, Obama couldn't keep it up - the rules being far stricter for presidential candidates than they are for editors of the Harvard Law Review. Thou must not set the wrong example. "Those choices were misguided, a serious mistake," he said, in a subsequent gloss on his original remarks. Hardly that serious, I would have thought, given his subsequent career - but then he couldn't really acknowledge the truth any more than Cameron could - that the wildness and curiosity were integral to their characters, not a deviation from them.

And since neither man came even close to addiction (a genuine ground for regret) I'm willing to bet that far from regretting their youthful derailments they harbour a rueful nostalgia for them as a badge of life lived. I hope so anyway, because they'd be the most awful prigs if not.

Is there a Timelord in the house?

When a deranged motorist was still in the frame for last week's letter bombs, a notionally sane motorist turned up on the Today programme to express, a little less explosively, the case against speed cameras. These instruments of the devil, he complained, had "criminalised thousands of ordinary people". I had no idea they were so malignant. I thought they stood passively until a motorist broke the law and merely recorded the fact. But, if we're to follow the logic of this man's remark, they broadcast some kind of thought-ray that forces "otherwise law-abiding" citizens to press harder on the accelerator. Surely it's time for the Government to act - and if they're truly powerless then they could always call in Doctor Who.

* I saw it reported last week that researchers at Manchester University had worked out a formula to account for the "beer-goggles" effect - in which factors such as "luminance of the person of interest" and the "Snellen visual acuity" of the goggler were algebraically mashed together to produce a prediction of the drinker's susceptibility to a nine-pint lovely.

Following similar recent "scientific" studies on biscuit dunking, the funniness of sitcoms and on-screen sexual chemistry the time is overdue for an investigation into bogus formulas. Let x represent the desire of a former polytechnic for a bit of free publicity and y the scientific gullibility of the on-duty news editor. Add x to y to the power of n, where n is a measure of the howling emptiness of the morning news list and divide the result by the square root of beta, in which beta represents the fondness of the researchers for Greek letters. The resulting number gives the FWOS Index or - for the laymen among you - the Factitious Waste Of Space Index.