It's familiar, but not enough that Castiel's made note of it yet. Either way, what he does know is that he doesn't like this one bit. If someone were to explain that he made Dean feel this way at one point, maybe he'd think twice about it in the future.

None of that is actually being communicated, but he has made a small crack in Dean's wall, at least enough to get an honest explanation out of him. It's an improvement from pure anger and dismissal, and so Castiel will take what he can get, even if he isn't completely satisfied by it.

Still, this makes more sense than everything else Dean's been saying. If Dean is struggling to not be distracted, to not get caught up on what the past has to offer, then that's something Castiel can at least understand, spoken in a language he knows.

He's not happy with it, which shows in the way his mouth twists downward. He's just going to make one last attempt, and then he'll leave Dean be.

"I can help you expand this place without you having to look at my face," he offers, half-hearted.