When friends asked me what I was writing this book about, I told them it was not about consciousness. After the age of 50, many neuroscientists feel they have sufficient wisdom and expertise to set about solving the problem of consciousness (whether or not they have ever done any experimental work on the topic). Being neuroscientists, they are concerned with the problem of identifying the neural correlates of consciousness and to show how subjective experience can arise from activity in a physical brain. Many solutions have been proposed, none of which have proved very satisfying. I knew I could do no better. That is why this book is not about consciousness.