But you still experience things when you sleep, hence are observing. Also, quantum insomnia should exist if you’re correct, but it doesn’t.
I don’t see how a Boltzmann brain spontaneously forming could ever be more likely than existing in a universe with all the infrastructure necessary to support a natural brain—even if that infrastructure beats some amazing odds, it only has to maintain itself. The theory further requires that mind unification be true.
I’ve been anesthetized twice. I don’t remember any dreams whatsoever, but I had the distant feeling that I did dream upon waking (though they may have happened as the drug was loosening its hold).