But it's not sufficient either, right? Just having memory alone also wouldn't prove intelligence, so it's not necessary or sufficient

I agree that memory alone is not sufficient to "prove intelligence".

Above, I wrote a paragraph sketching an example of complex behaviours, entailing creativity, humour, longevity, planning, memory, storytelling, object recognition, social skills, etc., as a "clear display of intelligence", not a minima, to use as a counterpoint to merely "recognizing a giraffe".

So I think you've missed my point, or, I've severely missed yours. If I have, sorry! As a general feeling toward internet nitpicks, we're unlikely to work in good faith to help each other out from here, so I'm out.

Well, the point I was getting towards is that if you remove the memory-based requirements from the scenario you set out, then it doesn't sound so far off from what something like GPT-3 can already do today. I am trying to reduce your scenario down to the minimal requirements so we can get a better understanding of whether those requirements are achievable by computers or not. If we just rely on "knowing it when we see it" then we might fool ourselves until the point where it's too late to go back.