I don't really understand what you mean by "fitness to surface" — Metaphysician Undercover
If I said dreams are autonomously moving signifiers called out of a
storage in memory, with no central agent, you would consider the arguments against that, but generally, you'd accept the possibility.
But if i said, so too are all of your so called experiences in your waking. Only in waking, these autonomous manifestations follow eons worth of evolution, such that they structure and project effeciently, following certain laws which serve their only function. First, the will to manifest (because the primordial, original or true nature of these images---the imagination---was to stimulate conditioned responses; built in was the drive to function or manifest). Following that, highly functional laws to sustain and promote the manifestations (all made-up by the evolved system), from difference, to cause and effect, reason, logic, grammar, and so on, and out of these, History.
Because dreams are just the outflow of the manifestations which have evolved not to stop, they do not conform to the rules which structure the ones in waking. So, the former seem to be what we would call random. They still signify, but that's another discussion.
The waking manifestations have been regulated, conditioned to follow a dialectic of such efficiency that only the images structured most aptly for the situation (given umpteen factors, run through speedy dialectic, conditioned trials and errors) get to manifest. That is, these operations of mind, are the most fitting to surface. To be simple, your eyes see a round red edible thing, your stomach may release triggers of hunger, etc. But these images stored in memory, autonomously flood those real bodily events with so called experience, their efficient constructions. And "apple" and the hundreds of corresponding structures displace the body with these Narratives. The "I" itself is just a structure which, in the promotion of manifestations, emerged as functional, surfaces a lot and so on. But it is just as autonomous a process in waking as in dreams.
They're both dreams, and in neither of them is "I"/ are you the real being. The body is and always is.