There I am bowling down the high street at a leisurely 45mph in the gas guzzler and, blow me, I pass a sign saying ‘20mph.'

For a moment I thought the old mince pies were on the blink. I've never driven at 20mph. Surely it's not possible? I've seen wrinklies with zimmer frames travel faster than 20mph. I've seen seaside donkeys move quicker. A tortoise with a hip transplant would leave you standing at 20mph. But blow me it's true.