Last night, I said something to my spouse about a conversation I had with a "single serving friend", and she didn't know what I was talking about. I said it was a Fight Club reference, then went farther and explained that I had a five minute conversation with a complete stranger (just walking down the street together), and I had to explain this idea to her, because she's an introvert and would never, ever engage in a conversation with a stranger.
How do you come to meet someone who seemingly doesn't have any way of meeting or interacting with others they aren't already acquainted with? How do you come to marry someone before you have this conversation to discover their lived experience of social interactions is so radically different to your own? No judgment, just a strange backstory that seems to raise more questions than it answers.
My spouse meets people entirely through her existing social networks - me, her existing friends, her dance community, and work. She doesn't just strike up conversations with complete strangers, it makes her very uncomfortable. Whereas I'm an extrovert and happily start or engage in conversations with strangers all the time.
She and I met back in the day through her boyfriend at the time (interestingly, we're still friends - he lives in town and we see him regularly). And she met him through her college roommate, freshman year.