I saw another traffic survey van today, sitting at the top of Cowley Road watching the world go by. I knocked on the window and asked them where the nearest 255 was. "It's not that kind of survey" they replied.

Almost immediately afterwards I saw a lorry with two men in the cab. In front of each of them, on top of the dashboard, was a number plate with their name on. Except it didn't have their real name. The one in front of the driver said Chaos. See if you can guess what the other one said. That's right - Mayhem! A lorry being driven by Chaos and Mayhem! Woo ha ha! I nearly fell off my bike, so tickled was I. There ought to be some sort of law against hilarity of this nature being flagrantly displayed on our roads. All around me pedestrians were falling to their knees in uncontrollable mirth. "Chaos and Mayhem!" they were saying. "It's a lorry being driven by Chaos and Mayhem! Someone call 'Little Britain', they'll get a dozen sketches out of it!"

I caught up with the lorry at the traffic lights and told them how funny I thought it was. "It's not a joke" replied the driver. "I'm Dave Chaos and this is Billy Mayhem."

Not really. "It's not a joke" replied the driver. "The words 'chaos' and 'mayhem' are in effect synonyms, and we use them to reflect the irony of the way society has us both labelled as simply 'lorry drivers' when, although we share an occupation, we are of course distinct individuals."

Not really. "It's not a joke" replied the driver. "I'm nicknamed Chaos because, like the first created being in Greek mythology, I have four children called Gaia, Tartarus, Erebus and Nyx. He's nicknamed Mayhem because he's a violent thug."

While they were stuck at the lights I nipped across to the Motorists' Discount Centre and had another number plate made up. I dashed back, leaned into the cab, and replaced the Mayhem plate with my new one - Theory. At which a butterfly landed on the windscreen and Guatemala was devastated by a hurricane.