It's really really scary gradually losing your memories.
It's the memory of your past that defines your current self.
I think Klaus just misunderstood things from his past life and not actually granting Elena's wishes. Elena made that "love" wish far away from Klaus afterall. But then I realize that maybe it's also not White that granted Elena's wishes.
White acted like he didn't know everything about being a Helper at first when Elena called him that, but then he suddenly really acted like the so-called Helper. Before acting like the Helper, White said that Elena summoned him and made him had to be reborn from an egg. Maybe the Boundary Stone became an egg because Elena wished it to be a egg. And remember that when the egg cracked, Elena wished for a "cliche white-haired Demon Lord."
Boundary Stone becoming an egg and the hatching of "cliche white-haired Demon Lord" happened before Elena even met Klaus, that's why I think Klaus didn't grant Elena's wishes.