At first, he tries to shake this off ‘I’m fantastic’, then he notes that Jody knows a thing or two, and he feels ashamed, so he gets to one of his best defense mechanism: snark, with ‘passing notes in class' but then he realizes Jody really cares, and something inside him changes. Usually, Dean would brush it off with 'I'm good' or some snarky comment, but instead he is saying: ’I appreciate that’.  This isn’t easy for Dean, accepting this kind of care, but he does. And this is a huge step for him.