We ALL need to be able to learn quickly or we simply don't last. If you've been doing this for a decade or more, you're guaranteed to have that skill in abundance, regardless of your origins.
What the OP was getting at is that you get exposed to a host of different ideas and paradigms in a proper CS program. Assembly, lisp/ada/scheme/etc., C/C++/Java, graphics, computer learning, computer architecture, etc.
I learned how to code when I was ten, but I would have never exposed myself to any of those things if I didn't focus on CS in college. What does that add? Exactly what the OP said. I know what I don't know. And it's a lot.