thoughts about somebody that I (used to) know

That moment of realisation when you understand that people who are nice to you at church or in Christian contexts actually dislike you.

Oh, they're nice because it's socially required of them, but they have zero interest in pursuing the relationship.

They might not kick you out into the darkness where there is wailing and gnashing of teeth, but they'd be just as happy if you vanished and never darkened their doorway again.