How did the man and the woman get to know each other?

M: Is this your umbrella, Miss?
W: Oh yes，it is．Thank you．I was looking for it just now．
M: You look a bit familiar to me．I wonder if we have met somewhere before?
W: Have we?
M: May I ask where you live?
W: Just two blocks away,in that tall building．
M: That’s it．I live there too．I am on the 8th floor．
W: It’s a small world．We live on the same floor．
M: I’m Adam Smith．May I know your name?
W: I’m glad to know you．Mr．Smith．I’m Lily Brown．