I actually learned Scheme in CS212 at Cornell (which, incidentally, I bombed at the time, but it was due to the pacing, not being unable to handle the depth), so it was pretty much a no-op for me.

Fundamentally it's a pretty simple language. Once you grasp those details, the rest kind of falls into place where you look at some code and go "Oh, THAT'S what it's doing".

I also answered your comment there.