WHEN the last of their three children was about to leave home, my parents decided to buy a smaller house. The real-estate sign went up. A week later, a second "For Sale" sign appeared two doors away. "Soon you'll have new families on either side of you," my mother remarked to the neighbour whose house was in the middle. "We're thinking of putting up our own sign," she replied wistfully. "It would read: 'Was it something we said?' "