It sounds like a nightmare: You're driving your black Eddie Bauer-edition Ford Explorer through a maze of roads lined with cookie-cutter, single-family homes. Slowly the houses melt together into a blur of fawn-colored stucco, garage doors, and sentrylike mailboxes. Perhaps you've passed your house several times already -- you cannot even recall whether you opted for the model A, with the picture window, or model B, with the bonus room. Your neighborhood, which has the hypnotic monotony of the ocean's rolling waves, has lulled you into a stupor. It sounds silly, but unless you're a homing pigeon or have Lewis and Clark's sense of direction, buying a house in Pembroke Falls could mark your mental undoing. But if the lure of this gated community intoxicates you, try putting a little red flag on your roof -- and hope no one else follows suit.