[etdgxcnc]

Myst, I would concur with those who feel that this was a mindsplit. It's a fascinating theory and RB covers it in depth in "Astral Dynamics."
I had the reverse experience, where as my physical body came towards consciousness, I felt an etheric invisible presence leap fully into me. It wasn't terrifying because it was in full daylight, but it was very visceral and unpleasant and my first thought was "eep! Something possessed me!" That kind of thinking almost ensured that I'd only retain the physical body's memories of the event, but my feeling is that my astral self was waiting impatiently outside my body for it to wake up enough for reintegration, and when it saw its chance, it DIVED IN. There was a mighty rushing feeling as reintegration occurred around the heart / throat area. I think it helps to understand what this phenom is from a rational perspective, thus reducing fear and increasing the possibility that the astral side of things will be remembered.