Curious double meeting

Last weekend I was in Berlin and a great coincidence happened. On Friday afternoon I took the tube from a relatively central station to one of the main ones (Alexanderplatz). I sat right in front of a girl of my age and left the tube without talking to her or anything. She stayed in the tube. Then, after dinner, at around midnight, I went to Alexanderplatz station again... and I almost crashed into her! We both realised this, smiled, said hi and went to our respective (different) platforms. This is a famous station, so it makes it more likely, but for this reason it is also a big station with several corridors, which I think makes it less likely. On Sunday afternoon I went to see some rests of the wall with a friend (one of the two most famous spots) and went into the museum about the holocaust next to it. And guess what happened...at some point we were reading the same poster next to each other! We then had to start talking and apparently this was the only touristy stuff she did in her trip (she was there for the weekend only) and went into the museum only because it was cold outside. I also went to that museum by total luck, as I changed my mind on what to do that afternoon in the last second. I did not have time to see very many things during the weekend and this was the only museum I saw (despite I did not consider going there when planning the trip). Is not this a great coincidence?! Perhaps it happens more often than we think but we do not remember the faces of the people around us...however, in all the occasions we were within a meter which must make the coincidence very unlikely!