"You should try the Pensieve," Theodore said. "Not just to remind him of those specific memories, but you never know what it could trigger in his mind. One memory could be connected to a thousand others."
He hadn't wanted to press it on them, not knowing exactly what kind of life Rosier led that he would be remembering. But Barty wanted those memories back, and so did Theodore. "I can leave a few of my own, to remind him about the infirmary, and who I am. But that's rather small, in the larger picture."