Strange co-incidence?

If you see someone today whom you don't know but seen face to face what is the probability that you'll recognize that person at a later point in life? Maybe 1 in a million. This happened to me recently when we went for a section party at a wonderful hotel near Hussian Sagar Lake. I heard this place is not open to public yet. I met this person R from my section and we started talking.

R, K : the usual hello how are you yadayada
Then R begins.

R: Where are you from?
K: Do you know .....?
R: Yes. I know which area?
K: Are you also from ...? I was in .... area
R: Yes. I know the place. (Curiously continues) Which street?
K: (I am surprised) Do you happen to ... street?
R: Very well. What is your door number?
A "kumbh mela" discussion! Gave my number.
R: (laughing) You know I was living two houses away.
K: What?!
R: I was living there for few years. We might have seen each other
K: Yes.

I don't know if it were our daily routines, individuality, the neighbourhood or the city life. We had never met as neighbours. I recall in childhood when I knew every family in the street. Something has changed the way people lived over years. Today Africa is closer to home than the neighbourhood. The realization brings in amusement.