That’s the trouble with seeing stuff, once you know you don’t want to see it, it’s already too late. We need an Unsee button installed on our brains. Visual coincidences — one thing looking like another — are especially tough. After you see it once, it’s like a catchy rhyme. It never gets out of your head. Now I can never look at Australia the same way again. But if I could unsee it would I really want to? Or would the world seem a bit less magical if we didn’t have a continent made up of a dog and cat head?