Sorry, to clarify, I was thinking of it as a kind of extension to what you said. Solas is incredibly intelligent and insightful, I think he would be able to pick things up in a way that most of us couldn't. Like how he beats Blackwall at Diamondback on his first game.
I think it's a combination of him being really smart, the Fade reflecting the physical world, and him just being withdrawn and trying not to attract attention.
I think he's been conscious in the Fade for a long time and has prepared himself for waking up. He knows how to dress, how to speak, how to carry himself, the big things that everyone ought to notice.
But no matter how hard he tries, there are little things he'll miss and will have him dumbfounded.
However, most of the time everyone's too busy chasing Cory and all that to pay attention to him. Plus, it can always be explained by him being this weirdo who spent most of his life in the woods.