And I think when he saw her at the end he realised his mistake (and that they do have a force bond) and Rey's angry at him again, so he bows his head in grief when the door is shut on him because he's done it again, pushed people who love him away.
I agree with it all. Hopefully we'll get to see more of the force bond between these two--not sure, though, since Snoke said HE was the one connecting them. Maybe they can figure out a way to do it on their own accord 🤷🏻♀️🤞🏻
"Why are you angry? Get lost. Ben Solo and little Rey in a speculative/AU setting at Lukes Jedi Academy, before he killed all the apprentices. Ben and Rey at least knew each other, possibly related or siblings?