Incidentally, I do the same thing with people. When I attended
a new school in a new neighbourhood back in '65, it transpired that
the boy sat at the desk behind me used to live just around the corner
from my previous home. We'd never met before, even 'though I used
to go by his house every day on my way to my old school. I later found
myself wondering if we'd ever passed in the street or waited in the same
bus shelter, or perhaps stood next to one another in the same queue
in our local newsagent's - without ever noticing (or remembering).
Of course, it doesn't matter a whit to the price of cheese, but
such things fascinate me for some strange reason.