Castiel wasn't really shocked by Meg being a little flippant or harsh, because she was Meg, and that was actually something he liked about her a lot. He was used to that kind of behavior in general as well, so it was just as reassuring as gentleness would have been, and more motivating.

He never shared much of anything unless he was pushed into it, and most of the time he wasn't. He would dance around a subject as long as someone else did, but if they truly kept pressing it--and it was because they cared, rather than any other reason--then he was far more likely to relent. Bobby, who Castiel missed so much, had figured this out right away, and Sam and Dean were catching on as well. Meg, of course, had always been direct, but now there's the caring as well, and after a few moments Castiel signed back once again.

It's a long story.

But he'd tell it, if she wanted to know.