Terry does know, he just didn't know he knew, until now, that is, when he does know. Well, that's presuming he knows now, but who knows if he knows he knows or doesn't know he knows, I mean, he could just plainly not know that he should know. Sooner or later though, he'll know for sure that he now knows that what he thought he didn't know he knew, and can knowingly laugh at his former non-knowing self. Figuratively speaking, you know.