MrMacSon wrote:I get the impression it was a serious pursuit in those days.
There are suggestions that some mystics, even in the 1st century CE, may have had "ascent" visions in which they would rise through the various heavens (or between defensive perimeters of a super sized castle encased by wall after wall). The gates through these heavens, or the gates in the walls of the castle, are guarded by angels whose job is to keep you out.
You have to know the password, which sometimes requires you to try numerous combinations of passages from scripture, until you get the right one, and suddenly the guard angel says "You, you can go in!" and waves you through, like the bouncer of a nightclub. There were generally seven heavenly gates, or walls, to navigate through. The goal was to sing praises to God with the other angels in the 7th heaven or palace.
As you get closer to the throne of God, you might get punished by the angel for a wrong password, which would result in having a ton of iron bars dumped on you. I you mistake the highly polished marble floor tiles for water, you receive a punishment (I forget what at the moment), but it was like you were drowning for real. It's a lot like a game of Dungeons & Dragons. Now sometimes God sends an angel to bring you over for tea, and he will help you navigate the gates and observe proper etiquette, like Ellen Page had to do with Leonardo DiCaprio in the movie Inception. If your friends who monitor your physical body as you mentally soar around feel you are having a "bad trip," such as the water trap, they might touch you with the hair of a menstruating woman and BAM! you are back to reality.
Some do not think that this kind of throne mysticism was practiced as early as this, but I think there was some kinds of practice of mystical ascents. The Heavenly Castle theme is present in the book 1 Enoch in a section usually dated 3rd century BCE. Of course, by the 2nd century CE, besides Jews, EVERYONE was ascending: Gnostics, Magicians, you name it.
I suppose you could call these ascents "dreams" but I think they are better described as trance-like states.
DCH