Most everything comes and goes randomly although it may at first appear otherwise, it's nothing more than an illusion.
Depends on where you are, what you perceive and what you think. Three orthogonal realms each of which contains three or more dimensions.
At any given time the mixture may vary significantly, one moment mostly in the first realm, and then the following moment in the next or even the next after that.
In total at least ten dimensions, but this could be many more. It could even be (much) less for all we know.
Only when we die do these variegated realms of reality fuse into a single element and then it disappears altogether, like a wisp of a smile.
This is the ultimate purpose of everything including you and me. Life is wonderful because it is long and complex, but it is short and simple at the same time.