This is the sentence in which I try to steer the thread back to he original topic. This sentence is my backup in which I blather unrelated, anecdotal stuff from my workplace, because it just popped into my head and I have the slight feel that my first sentence won't meet his purpose.
You know that saying "everyone knows everybody over 6 other people", maybe something about that. Or: who of your friend's friend's friend's has the same hobby / whatever.