It's context switching, I face this daily due to my OCD. The damn doorways are always a problem.

I'm not very well versed on this subject, but have there been any experiments conducted with a doorway in the middle of a basketball court or a field?

I'm sure that would mess me up for a good couple of minutes as well. It's not just doorways that lead to a different room, it's just the fact that there's a doorway present, that changes my context of things.

Maybe I'm the weird one.