"I Just Need Space": Why the Same Closed Door Means Refuge to One of You and Warning to the Other

They went quiet. Not angry, just gone. They need the room to themselves: no touch, no conversation, no being needed, for forty-five minutes. You stand outside the door wondering what you did. You did nothing. They are not punishing you. They are trying to hear their own thoughts, which got drowned out by a full day of being around another person, even one they love.
But you do not process space that way. To you, closeness is safety and distance is a warning sign, so when they close the door your nervous system reads it as the first sentence of a goodbye. You knock. "You okay?" They say yes. You knock again ten minutes later. "Sure?" And now the space they needed to recharge has become space they have to defend, and defending it costs more than the recharge was going to give back.
Two facets are colliding here. Their pull toward solitude is the Gregariousness facet of Extraversion running low, so people-time depletes them and alone-time restores them. Your knock is the Anxiety facet of Neuroticism reading a closed door as a threat that has to be checked. One of you is refilling and the other is spiraling, same forty-five minutes, completely different experience.
The fix is putting a shape on the space so it stops feeling open-ended. "I need forty-five minutes and then I am yours" gives the recharger their room and gives the worrier an endpoint to hold onto, which is the exact thing the anxiety needs in order to stand down. Space is not rejection, but it feels identical to someone who learned that silence means something is wrong. Named and time-boxed, the door stops being a verdict and goes back to being a door.
You can see where each of you lands on Gregariousness and Anxiety with the 30-facet OCEAN personality test. It takes about 15 minutes, the domain scores are free, and a compatibility report shows whether "I just need space" is a real distance or two nervous systems reading the same closed door in opposite languages.