Right, dissecting why that answer would be worthless is part of the fun of the thought experiment. It seems like it should be ... spectacularly interesting to somehow discover that your entire memory is a lie and the world you're in is radically different than you thought, but the fact you can't do anything with that knowledge completely neuters it. It implies that in the calculation my mind does about how much I care about a possibility, there's something like a term for "how much control (or even a vague casual connection) do I have over the world?" that everything or nearly everything else is multiplied by. Even if a deity told me I was a Boltzmann brain, I would still hang on to the minuscule chance or delusion that I was a human and still process decisions that way, because in some sense I fundamentally can't care about a situation where there's zero utility to be gained besides as a curiosity. It feels like this might be a useful intuition pump to think about concepts like motivation and learned helplessness. The fun in a thought experiment is how it gives you a new lens to view other concepts with.

I don't understand the point you're trying to make in this post.

Yeah, I kind of went off the rails there, didn't I?

My point was merely: How do you recgocnize a brain (and its very special cousisn the BB) at all? I wager it's just because you see a human before you. But if you really want to question things... then you're in for a very bleak time.

Just like one can't disprove solipsism, one can only brush it aside as pragmatically useless. Just because a theory is internally consistent or even accurate, does not mean it is a good all-around theory: simplicity and elegance counts too. And having to agree on who is the solipsist among all figments is inelegant and an impossibly complex task.

> According to the most extreme form of this view the only way by which one could be sure that a machine thinks is to be the machine and to feel oneself thinking. One could then describe these feelings to the world, but of course no one would be justified in taking any notice. Likewise according to this view the only way to know that a man thinks is to be that particular man. It is in fact the solipsist point of view. It may be the most logical view to hold but it makes communication of ideas difficult. A is liable to believe ‘A thinks but B does not’ whilst B believes ‘B thinks but A does not’. Instead of arguing continually over this point it is usual to have the polite convention that everyone thinks. -- Alan Turing

> Just like one can't disprove solipsism, one can only brush it aside as pragmatically useless.

Agree.

> Just because a theory is internally consistent or even accurate, does not mean it is a good all-around theory: simplicity and elegance counts too. And having to agree on who is the solipsist among all figments is inelegant and an impossibly complex task.

Indeed not... but the true measure of a theory/hypothesis is how hard is it to vary to explain new facts. (I think this idea is due to Peter Deutsch, originally.) If you can change your explanation by saying things like "Ah... well, Aphrodite wouldn't do that because she's pregnant in Spring"... then I'm sure we can agree that it's a badly or unfounded theory of the world.

This is actually an extremely high standard that very few pass.

Thanks. I'd never considered adaptiveness of a theory before and I like it. Perhaps adaptiveness at times emerges spontaneously from simplicity / regularization. But it is good to keep it in mind from the very start.

Don't we experience reality as if we were a Boltzmann brain anyways?

How many of us remember the first moment we became conscious?

Yes... and there's really no way to tell unless the simulation actually tells us.

An easy test for this is to ask anyone who's either on mind altering chemicals, or schizophrenic[0]. That makes it clear that you are really perceptually bound.

[0] I don't mean to say that these are even close to the same thing. I just want to pick two extreme examples.