Charlie's Christmas Letter is a little document in the form of a letter to my grandson, which seeks to answer the questions that a bright teenager ought to be asking: Why were the shepherds in the fields in winter? Who were the three wise men? Why do we bring holly into the house? Of all the ways of entering a house why does Santa choose the chimney? What is the Messiah about? Why did Tchaikovsky drink unboiled water during a cholera epidemic? What...