[namandixit]

Why would it matter though? I read a analogy somewhere (in a Carl Sagan's book, I think) about how a goldfish in a convex fish bowl might create a set of rules for motion of objects that will work fine in predicting motion of objects as seen from inside the fish bowl but will be totally different from the true laws that people outside that bowl will formulate. As long as the rules keep working for the fish, why would the fish care if they are wrong? More importantly, how would you know that you are living in the outermost layer of reality? (not sure what the technical term should be)

As Vladimir Bartol famously opined: "Nothing is true."

[balabaster]

How do we know for sure that we're not in the Matrix? Can we be sure? Does the very fact that we question our reality confirm our sentience or are our thoughts merely the output of algorithms we've been programmed with from the outset?

[lmm]

> How do we know for sure that we're not in the Matrix? Can we be sure?

If we observe no effects then the most parsimonious explanation for our experiences is that we're not. We can't ever be sure, because someone could be in the Matrix and have absolutely identical experiences to our own. Occam's Razor tells us what's most likely (and you can get more specific than that, putting numbers on it - see Kolgomorov complexity), but it's not 100% reliable.

> Does the very fact that we question our reality confirm our sentience or are our thoughts merely the output of algorithms we've been programmed with from the outset?

Try reexpressing that question in terms of something you could empirically observe. If you can't, the question probably isn't meaningful.