His question hit home, even though he couldn't have known where exactly he needed to aim to do so. Her entire life was a case study of their opposing theories, and she had to admit that he came out on top on this one. Even now, with nearly a year and quite a bit of healing under her belt, she had to spend quite a bit of time quelling her anxiety and keeping it in check, just so she could run Arendelle properly. Now that he'd pointed out the connection, it was clear for her to see that the constant worry she experienced as queen didn't help with her anxiety problem.
"You have a point, I'll admit. Constant worry isn't good for anyone. But wouldn't you say that a life without worry causes its own problems? I think that, even if we shouldn't do it constantly, we should worry about our current predicament. We're in a terrible situation. Not worrying is dangerous." She'd never be the girl who could see the joy in a carefree existence. Lowering your defenses that completely? It was just asking for trouble.