Perhaps when you Astral project or have an OBE,your awareness is remembering thoughts and feelings from when it is in contact with the brain,I dunno,but what I remember feels like yesterday, I'm 61 now, a dream wouldn't stay with me for that long.
Maybe when you A/P or have an OBE,it feels out of this world as it's just your awreness remembering all it see's and when it returns to your body,your brain try's to put reason to it.
