"Temporal linearity"
Nicely put.
We have no proof, but I have dreamed of different lives, some in the past, some in the future and I have dreamt of other dimensions.
Even those that have passed over come to me, so we really have no idea of what our physicality really IS or the time/space we inhabit.
I guess that's why science fiction appeals to so many of us.
You oughtta try to live my life for six months or so with my psychic sensitivity. You'd start looking at the universe in a whole new way.