I saw someone on the tube the other day with a penguin tattooed on her arm. It was quite well done, with shading and perspective. In fact, it could easily have been used as an illustration in a school textbook.

Seeing her made me surprised all over again at how popular tattoos are. They’re basically pen-and-ink drawings or little calligraphed mottoes that are embedded in your skin forever. What seems odd to me is that people aren’t generally all that keen on pen-and-ink drawings or little calligraphed mottoes in any other context. If you asked most people to choose a drawing by a competent but mediocre draughtsman and then display it on their living-room wall for the rest of their life, they’d refuse – especially if it was expensive and involved hours of pain. But if, instead of their living room, the drawing goes on their body, they’re really keen. I couldn’t imagine the penguin lady buying a print of the same drawing and putting it up on her wall.

There’s another kind of tattoo that I find much easier to understand. In a pub in Hackney the other day I saw a man in shorts with a huge lighthouse tattooed up each leg. He was in his twenties and the tattoos seemed to me to be a huge pre-emotive practical joke on his future self. He was basically saying, “You’d better continue to find this hilarious for the rest of your life or you’re fucked.” It was a way of making sure he doesn’t turn into the sort of person he dislikes: i.e. someone without huge lighthouses tattooed up both legs.