He was a sorcerer from somewhere nobody knows, he had a memory about someone from his childhood yet he kept hold of it forever

He had a goal of finding that someone which was you, he built a whole moving castle just to find you. Joined various of castles just to hope one of them is yours. And yet one day, he finally found you.

He knew about you and your 'curse' yet he wanted you to found out who he was yourself.