I wonder: am I authentically a person who swears when she messes up her pedicure? Or have I become one because, all those years ago, I said I was? I thought of that moment, too, while reading Emily Bootle’s new book, This Is Not Who I Am, an examination of authenticity in the digital age, which attempts to suss the “realness” of everything from politics to personal brands. One early definition of authenticity, offered in the book’s introduction, is drawn from Rousseau: that you must not only be who you are but be seen to be who you are.