Hee! Thanks for mentioning the title--it is kind of vicious, isn't it? I love all the standard tropes for precisely the reason you identify. But with amnesia, I think there's an irreducible difference in the amnesiac person, so the person whose reactions are most interesting to me is the one who remembers. And I agree with you: Dean's diagnosis at the end is right, even though it's not the whole story.

And yeah, the Trickster was just thrilled to find this latest piece of misbehavior.