I have always found the transformative Gates from Sumerian myth fascinating, and especially the idea that Earth was not a realm of death. Given that characters are still able to be killed, I would venture the suggestion that most of the experiences told about in the non-death mode were those of the Faerie Race. Mortal humans come into it in different ways and, for the most part, experience the Faeries as haughty and extremely polarized (typical of a civilization's end times).
The Gates document the levels on which the psyche exists. Inanna, Goddess of Love, is able to travel (project) through the Universe by contracting and expanding her awareness.
Recently, I sensed that the film Inception (starring Leonardo DiCaprio) could be related to these stories of Descent and Ascension through the levels of "dream" (existence). I specifically enjoyed the depiction of the event speed difference in those levels - a reference to Frequencies?