Since I haven’t had another experience similar to this one, it hasn’t been possible for me to discern any kind of pattern in how such things work.
   
I do find it noteworthy, though, that my introduction to the realm of meaningful dreams had some key differences from Granny’s many experiences of this type.  First, while her dreams were symbolic, mine was very literal.  Also, while hers reflected things that had already occurred, mine was predictive in nature.

My hypothesis at this point is that maybe I’ve genetically acquired only some of her capabilities, while having also picked up some from other sources—and that these are the ones which have enabled most of the other experiences I’ve described in this account.

I feel the car dream was an important gateway to the other experiences, though, by opening my mind to the possibility of other dimensions in this world beyond the more obvious and easily verifiable ones.  Without this experience, I would probably never have  considered the possibility of thoughts originating outside myself.