"My Father's house has many mansions" means there are dimensions you do not remember visiting. I use the word "dimension", but that does not say accurately what I mean to say. There is no word for what I want to say.

It is like — only like — you have a house with a third floor you are not aware of or have forgotten (not aware of and forgotten are the same) — and then suddenly you open a forgotten door (you have an insight) and there are the stairs, and there are the other rooms, treasures there all the time, but hidden from your view. They can only be hidden temporarily.