If the answer to "did I lose my memory for some kind of reason" is "no," doesn't that sort of make it sound like he didn't actually lose any memories? This chapter may be about answering questions, but at the same time it definitely is a bit difficult to interpret.
Honestly, the impression I'm getting is that the "no response" questions are probably the ones that are best to focus on right now. I'm especially interested in its answer to the question of "are you aware of a country called Japan." Because while for other questions the lack of answer could be interpreted as not understanding what the question was asking about, (as is confirmed for the game world question) if that's what's going on here, then why couldn't it just answer no? After all, the question was "do you understand what I'm talking about?"
So I guess the answer here is probably something a bit more complicated than "yes" or "no" for the question of whether or not the "tyuoion" knows what Japan is. So if that's the case, what's so complicated about the answer? Maybe it knows a Japan but it doesn't know Ryouta's Japan? In which case, would this be an alternate universe? But then, if it knows that he's talking about a different Japan, doesn't that mean that it does know of his Japan, and should have just answered "yes?" So that theory doesn't really work.
But are there any theories that can properly reconcile both halves of "can't say it knows what Japan is" and "can't say it doesn't know what Japan is" without also being another sort of "not exactly..." that requires it to know what he's talking about in the first place? (Which would lead to an answer of "yes?") I honestly can't think of any right now. It's an interesting puzzle.