I never said completely. Sure it’s fun to entertain such possibilities, but science doesn’t bother with unverifiable claims. That’s the realm of metaphysics, unless somebody clever or lucky finds an actual glitch in the Matrix which would allow the claim to be verifiable.

Boltzman brain sure is an interesting concept. If I am one and you’re a thought within it, then I must say that it’s a bit funny that it popped into existense with the correct theories of thermodynamics and cosmology that explain the brains own existence. Also means that the universe has seen or will see every possible brainstate, nightmare and daydream, infinite beauty and horror. Oh yeah and we may as well be living in a Boltzmann galaxy that popped into existence in a similar manner. But alas, the relative improbability of our own (non-Boltzmann brain) existence is not proof against it. Same goes for the simulation hypothesis.