But we all talk to ourselves constantly—most of us merely have the good sense to keep our mouths shut. We rehearse past conversations—thinking about what we said, what we didn’t say, what we should have said. We anticipate the future, producing a ceaseless string of words and images that fill us with hope or fear. We tell ourselves the story of the present, as though some blind person were inside our heads who required continuous narration to know what is happening:
