External World Realism!

My view on perception of the external world for some time was "The fact that we see the world in a certain way is evidence for it being that way. However, there is no way to actually know we are not being deceived in some way. That said, there's no particular reason to believe that the external world would be some particular way which does not correspond to our perception of it, so it is most rational to act according beliefs based upon what we actually see." To an extent I still believe that, but this morning I was re-listening to Map and Territory when it suddenly occurred to me:

Any theory of how the external world is, must not only explain how the world is, but also why we explain it precisely as we do.

That means that any complete description of the external world must contain within it a complete description of what we perceive to be the external world. Hence, by Occam's Razor based on Solomonoff Induction, a "naive" view of the external world, that it is as we perceive it to be, must be the favoured explanation of how it actually is.

Apologies if this seems either obvious or arcane, but it means a significant amount for my confidence in my ability to know the world.