I guess to me, I see him as the one solid in her life and to have his whole perspective on her/care for her shift like that seems to me like it would be harder than him not remembering her. She's got more experience with changing herself or helping him be himself or memory being fluid, I would think, than the other.

:shrugs: I think it depends a little on your core reading of the characters. Either side would hurt. That one seems worse to me though.

I know it was easier for me to lose loved ones due to growing apart, memory loss, death than through radical relationship shift that left me with not only nothing left, but what I originally had tainted.