Wait so, she wish for him to never forget her and she pay with her memories and he wish for her to get cured and he didn´t pay? or was the payment just seeing her forget him?
@KiTA@Zasgan12 I think,it was wish consequence that either her or both of them would forget about their relationships, not hers. There was a part in the reply sent to him, that stated what was to be taken, so at least he knows his own wish results. It still lefts us wondering, how did her wish backfire, there is no direct information.
By the way, maybe it's because of her wish he didn't forget(considering his wish led to both of them forgetting).
I think his wish would take only his memory, but her wish saved his memory in exchange for her memory
He talks a lot about forgetting her, so he probably knew the consequences of his wish