Imagine yourself seated on a patio overlooking a large public square. You are enjoying evening drinks with some friends before you run a few errands on the plaza on your way home for the evening. While you are seated, an old acquaintance happens by on their way to pick up a few groceries. They sit down and join in the conversation for a little while, watching their child play at the fountain a short distance away. As the sun sets everyone pays their tab, says their good byes, and heads off in different directions.