Perhaps, for instance, you meet a lovely, conscientious couple with three children, and find yourself blurting out that child car seats are a waste of time and money (at least that’s what the crash-test data say). Or, at a holiday dinner with your new girlfriend’s family, you blather on about how the local-food movement can actually hurt the environment—only to learn that her father is a hard-core locavore, and everything on the table was grown within fifty miles.
