Another genealogical coincidence

I had been working for many years on all lines of my family. I was at a dead end with one of them, even on message boards, nothing was showing up after 10 years of my posting. I stop looking, then a few years later, decided to try again. There was no answer to my posting but other people were asking questions about others and a few sounded like they might have been in the same area (with the same last name) and one woman was answering those questions but the postings were cold (a few years old). I decided to try to contact her anyway and it turns out she's an expert on that family, has been studying it for years, contacted my great aunt for information back in the 1960's, and since then has found the family history back to the 1600's. She is a descendant of the brother of my immigrant ancestor who came over in the 1740's. The next part of it was...I told my aunt (now divorced from my father's brother and remarried for several years) about the progress I had made with that family line. She told her husband and he reminded her that he had met that woman on a plane about ten years before that. They had talked about where they were from and she said, "Pennsylvania" and he said "my wife is from Pennsylvania" and she told him what lines she was working on, and when he recounted it to my aunt, she said that's one of my ex-husband's lines. They never contacted her, but remembered her name when I told them the story. I have been in touch with that lady, a gifted genalogist for several years now and have received and given much information back and forth.