And then, unbidden, seemingly out of nowhere, a thought or image arrives. Some will float into your head like goldfish, lovely, bright, orange, and weightless, and you follow them like a child at an aquarium that was thought to be without fish. Others will step of the shadows like Boo Radley and make you catch your breath or take a step backward. They're often so rich, these unbidden thoughts, and so clear that they feel indelible. But I say write them all down anyway.