I. The way, as I said, that Gail Caldwell employs metaphor in Let’s Take the Long Way Home: A Memoir of Friendship is remarkable. Almost every page includes one. “No, you’re not,” said Caroline, her face as deadpan as a coach’s in a losing season. “No, you’re not. Keep your hands together. Stay still—don’t look at the water, look at your hands. Now look at me.” The voice consoled and instructed long enough for me to straighten into position, and …