One Monday morning recently I was on my way to attend a conference that was due to begin at 8.15am 70 miles away, so it was a very early start and a bit of a trek to get there.
I remember seeing a young policeman pointing some hostile-looking gun-like object in my direction as I drove.
My memory is that I had just come off a motorway, that I had reduced speed, in fact that I was driving behind a bus, taking it very easy. But yesterday I got one of those ghastly 20-page printed forms telling me I was wrong. That it had been a 30mph zone. And I had been doing 35mph. So the policeman had trapped me.
No doubt he was given a target, and I helped him reach it. Well, hooray for him. And for me, a fine, or attendance on a speed-awareness course. Obviously, I will opt for the latter.
But it rankles. I am not usually a conspiracy theorist. I believe that more bad things happen through cock-up than conspiracy. Except when it comes to driving. There, I really believe the police conspire against us motorists; they choose the trickiest locations - the ones where the speed limit suddenly reduces - to catch the unwary.
It's happened to me before. In London there's a fabulous trick where Marylebone Road lifts itself wearily to join Westway, and goes from 30mph to 50mph. How you are supposed to do that without passing through 40mph? That time I was done for doing 39mph. Fabulous use of police time, that.
As you can tell, I'm no Jeremy Clarkson. I'm a notoriously slow driver, the typical old-lady driver that gets hooted at because I stay 5mph beneath the speed limit (when I know what it is).
But in these days of variable speed limits, it's getting pretty difficult to work out your 20mph limit from your 40mph limit. Which means, goody, goody, more money for cash-strapped local councils, which they will not spend on helping children or the elderly. They'll use it, no doubt, to pay more policemen to stand by the roadside and point speed guns at little old ladies like me.
I could fight. But what a waste of money that would be - a full court hearing while I try to prove that blooming speed gun was calibrated wrong. It's far quicker, easier and cheaper to give in. That's how the jobsworths always win.
And the Olympics played straight into their hands. First they painted huge rings on motorway lanes and city streets, then they put up enormous signs telling us not to worry, they are not in force, then sneakily they brought some of them into force when we didn't expect it and, hooray, they collected even more fines.
Nearly two weeks before the Games started, an Olympic lane on the A30 was craftily brought into service and police fined bewildered motorists who strayed into it £130 apiece. Just the thing to make us all feel ecstatic that we were hosting the Games.
The trouble is that while other nations happily flout such idiotic rules, we British are way too obedient. British jobsworths triumph because they know it's too much trouble to fight them. They also know that the programme that used to pillory them, that actually brought the word jobsworth into general use and after which this very column is named, That's Life!, is no longer on the air. So jobsworths reign unchecked.
I don't approve of speeding. If I'd been doing 40, 50 or 60mph, yes, indeed, trap me and punish me. But what annoys me is not just the cost of a young policeman wasting his time standing on the side of a road with a speed gun when he could be doing something rather more important, but that the jobsworths are smacking their lips and making up yet more rules to trap the unwary. Bring back That's Life!, I say. Before I get fined for saying so.