Childhood acquaintance

About 12 years ago, I was invited with my then husband and child to a barbecue, in a very rural part of Perthshire. Although I have lived in Scotland for many years, I am actually from the south of England. I didn't know the people holding the barbecue, but was invited by a mutual friend. Also at the barbecue was the mutual friend's sister, with her husband and children. Whilst talking to them, I learned that although they were Scottish, they lived in the south of England because he was in the Navy. We were talking in a group for some time, when I started to think I had met the husband before, and we were about the same age. We couldn't think of any place, such as university, that it could have been, and the conversation moved on. However, later when we were talking about his career in the Navy, I mentioned that my uncle had been in the Navy, stationed in Dartmouth, Devon. At this point, he asked my uncle's name. His father had also been in the Navy, at Dartmouth. His family and my uncle and family had lived next door to one another! We had in fact met before - about 25-30 years ago as children, when I had stayed with my cousins during school holidays! That we should then 'randomly' meet at the opposite ends of the country seems quite extraordinary to me, especially that I had felt that he was familiar. In the last 5 years, they have moved back to Scotland and our children are now at the same school.