I held the elevator open for an elderly lady entering the building. She thanked me, and saw the floor that was already active. Her apartment was on the same floor, she said. I exclaimed "Neighbors!", to which she smiled and said, yes. On reaching the floor, we discovered that we live in flats directly opposite to each other. We got talking; what I did and where I was from. Turned out, she lived in New Delhi with her husband for 5 years! I told her about my internship there for a couple of months. She could even tell the neighborhood she was in, which was pretty close to where I lived.
Incidents like these make you realized that the world's not that big of a place. This entire conversation took place in German (at least I tried to) which was kind of a big deal for me. New language skill put to good use!