How do you know I’m an idiot? Take a look at my right calf | Zoe Williams

My bike has left me covered in grease - or, as the old hands call it, a Cat 5 tattoo'

For about six weeks, I had been cycling at a very stately Miss Marple pace because my brakes weren't working. I assumed the brake pads were worn and meant to replace them, but in the interim found my left foot worked just as well, as long as I wasn't on a hill. Until, one day, inevitably, I was. Hair-raised, I took the bike into a shop, where they said nothing was working at all. The cables had perished. Then they fixed them, which is hands-down the most my life has ever been saved by a shop. I should swear an oath of fealty to them, like a knight.

Anyway, it's good, because now I can pick up speed, which is exactly what you want when you are glad to be alive. That is how I got my Cat 5 tattoo" - a greasy chainring imprint on the inside of your right calf. My brother-in-law introduced me to it gleefully because it's meant as an insult. If you were a proper racer, in categories three or four, your chainring would be clean. If you were a better racer still (in categories one or two), your calf wouldn't be anywhere near your chainring. But, because you are a novice and an idiot, you have grease all over yourself in an attractively symmetrical pattern. It's also called a noob tag" because why have one piece of jargon when you could have two?