You can substitute Boltzmann pine trees or Boltzmann gold ingots for Boltzmann brains: the idea is that something of high complexity fluctuates into existence f

You can substitute Boltzmann pine trees or Boltzmann gold ingots for Boltzmann brains: the idea is that something of high complexity fluctuates into existence from a (vast! vaaaaassssssst!) thermal medium. The crucial point is that a small arbitrarily complex pattern repeated often is a lot more likely than a much larger pattern in which these smaller complex patterns evolve. In physical cosmology, the Boltzmann brains issue is: how can the sky full of many galaxies (in which solar systems form) instead of many many many more complicated things (automobiles? space probes?) that were not produced by the operation of processes within galaxies? Why isn't the sky full of gazillllions of space probes with nearly zero galaxies? Instead, in practically every direction we look, we see trillions of galaxies, and (at least for now) very few space probes. (That these galaxies may end up being populated with lots and lots of space probes eventually is the point.) We can coarsen and run into the same problem: why are stars organized in galaxies (and clusters of galaxies) rather than appearing randomly throughout the cosmos? The latter is much much much more likely in fluctuation theory. You can substitute a sparse cold non-self-interacting and generally non-interacting gas that occasionally condenses briefly into patterns that look like a small snowman, compared to much larger and more complicated patterns (perhaps whole armies of snowmen aligned rank-and-file) if you prefer not to think too hard about intermolecular and similar forces, and want to whittle down some your objections about how thought and memory might work. > my hypothetical disembodied mind has no reason to assume its own thoughts/memories/etc must be stored somewhere Which is why I asked you to imagine putting the idea to your friendly disembodied mind in order to get said mind to consider that and reply with its thoughts on the matter. Having been asked, it then has a reason to ponder (admittedly not assume) that its own thoughts/memories/etc must be stored somewhere.