"It is a small world. You do not have to live in it particularly long to learn that for yourself. There is a theory that, in the whole world, there are only five hundred real people (the cast, as it were; all the rest of the people in the world, the theory suggests, are extras) and what is more, they all know each other. And it's true, or true as far as it goes. In reality the world is made of thousands upon thousands of groups of about five hundred people, all of whom will spend their lives bumping into each other, trying to avoid each other, and discovering each other in the same unlikely teashop in Vancouver. There is an unavoidability to this process. It's not even coincidence. It's just the way the world works, with no regard for individuals or property."
Anansi Boys, Neil Gaiman