If that was really your first vivid dream, I'm surprised. I wouldn't be
a bit surprised if the fact that you are pursuing "growth" (all growth
and change is spiritual growth - you and everyone else is an eternal spirit
residing in a temporary temple, your body) it can easily begin to stir up astral
experiences. There are all sorts of ways to "incubate" a dream,
create one that you want. You can also program yourself to remember your
dreams and I'm sure that you've had many others that you don't remember.
Use a slight meditative state or perhaps in your Course in Miracles you have
some other method, but tell yourself what you wish to dream about. You can
also program yourself to take control of your dreams - which I've done on
occasion. There are web sites about all of this and books too. Just
try and avoid the woo woo entities that are out there. It doesn't have to
get complex ore even difficult.
I can remember dreams from infancy and in my chaotic world of those days,
many nightmares too. A "nightmare" or bad dream is simply
yourself as spirit trying to get your attention to listen to a message.
The astral world is a wonderful reality.