It happens. I was once in SF talking to a total stranger from LA (pop ~4m) and when I mentioned I grew up in Dallas (pop ~1.3m), she said "oh, do you know [X]?

It happens. I was once in SF talking to a total stranger from LA (pop ~4m) and when I mentioned I grew up in Dallas (pop ~1.3m), she said "oh, do you know [X]?" And I did.