Neuroscientists have been studying the weird capacity most people have of "visualizing", or mentally conjuring pictures of things that aren't there, for a long time. That decision led to me spending an inordinate amount of time deep inside an MRI, looking at pictures or trying (and failing) to imagine pictures. A few times during those experiments, I came up with so many ideas—things to write about, better ways to explain things, new intriguing questions about the world, etc.—that my biggest worry was trying to remember them all for the 20 or 30 minutes left until the end of the session.