(almost) impossible encounter

I live in London. The event happened in May 2010, I was travelling with my wife and my child in Boston (Massachussets) for our holidays. Our journey was not associated to any professional activity. I was visiting a friend with whom I did (some) of my studies in Paris. During our visit our friends suggested us to visit the Museum of Natural History of Havard University in Cambridge. During my visit, I suddenly and unpexpectedly came across a person with whom I have some regular professional contacts and relations. This person is American, he is a physician from California. He currently works and lives in Tokyo. He happened to study chemistry in Havard and was invited by the Alumni to celebrate a special anniversary at the Havard University. He was taking the opportunity of his journey in Havar to visit the same museum. We were both in complete disbelief (it took me several hours to get over this incredible experience). We have of course taken a picture to celebrate and immortalise this almost improbable encounter.