When on Holiday in Eygpt, we were sat by the pool, a man sat near us with his family, asked where we came from as he recognised our somerset accent, I told him and said but you wont know our small village, he replied oh yes I do, I know someone else from there I work with him, he was one a colleague and friend of my cousins!
A few years ago I used to work with a statistion (not sure if thats the right spelling) he always said if you take a group of 25 people at least 2 of them will have family members that share a birthday, we didn't believe him so we tested it, although there were only 6 in our office , one of the women shared a birthday with my DIL and another with one of my DGD's