"Uhhh. Well, last time I had memory loss issues, my friend Blaze had to help? I can't say how exactly it worked, but it involved fire and her using the Sol Emeralds that she guards in her world."

Not super helpful, alas. He rubs at his neck a little awkwardly and tries to offer a... slightly more practical solution?

"Have you tried hitting your head on something really hard? Though... now that I think of it, that might just make it worse..."