Even if space is expanding and time is irrelevant to a photon, time is relevant to humans and space is fixed in overlapping 3D grids for us.
Hence, why we don’t always remember our dreams: They’re no mental star to hang the dream off of and no effect -back-to-> cause we can mentally walk back to.
Lucid dreaming gives you that ability, but, well, sometimes we don’t always bring the observer/narrator voice in with us to the dreams, and so… they just… happen. When you wake up and they’re gone…. well, they’re not *gone*.. they’re just a file without a filename and no datestamp. But it’s there, and your dreams will make themselves known in other ways.