>>49240270
Have you read A Beautiful Flower Blooming Violet Every Sixty Years? Yukari is almost demented. Jokes aside, this is more relevant quote than the pic:
> I knew what was happening because something like this had happened sixty years ago, too, but recalling the sensation as it happened made me uneasy. Still, it's not as if all memory of the incident would vanish. Any events left to "the record" would remain, but any other "memories" would begin to fade.
>Events left to the record. In other words, history. Anything that passes the sixty-year boundary becomes mere history, and history is a collection of unusual events. Time grinds to a halt during these unusual events, and this is why time practically stops at points past more than sixty years ago. Or, to put it another way, what is "ordinary" has a normal lifespan of about sixty years. My memories of more than sixty years ago vanishing means that the death of their "ordinary" qualities is at hand.
>But, why is that cycle sixty years? I thought about this sixty years ago and I have the feeling I came up with a theory, but perhaps due to the onset of a senility I can't remember what it was.
This is probably the closest we have to how youkai memory works. Events that are from a previous Gensokyo cycle are forgotten unless they were unusual enough to become a history. Now, this sadly doesn't exactly answer your question, because we don't know what is a bar for unusual event. Furthermore, if unusual event doesn't make waves (because nobody observed it, for instance), would it become history or not? Finally, there is a possibility that because Maribel's experiences aren't history yet, then Yukari forgot about all of them.
Still, I would confidently bet on that Yukari doesn't remember anything from Maribel's more ordinary parts of life.