Sonny is usually the reason everyone is in danger - but now, he is needed in PC! But then, he does not remember who he is, so how can he carry out Sonny's beneficial effect in PC? LOL.
The usual amnesiac story usually has the characters forgetting the amnesiac doesn't remember them, and so does not miss them, love them, and so on.
But then, he can still make his super duper special awesome sauce. He remembers that.