The City

I don't understand how DSM can be so big yet you run into people you know. Today I was walking the skywalk with my work friend and I ran into my old roomie's boyfriend. This is the same old roomie who would go through my room when I would go home for the weekend. That hasn't been the only time that she has crossed my path since I moved out. Her and her bf also live in the same town house complex as Beau's best friend. It is almost like me and my old roomie are meant to cross paths. Why?