I loaded up with theory classes in college precisely to stretch myself and learn more of the difficult things that I wasn't yet already competent in. I'd been programming since I was 9, and could handle the programming projects just fine (more easily than most other students), but the theory classes were more challenging and I wasn't going to learn that stuff if not in school. It ended up being quite helpful for Google interviews later anyway.

I didn't go to Google but I can relate to your story. Having reached CS courses after tens of thousands of hours programming was very enlightening. Indeed, the CS course layed down all my hands-on knowledge upon a very nice theoretical foundation. I clearly remember saying to myself "ahhh, all that what I've done so far, now i really get it". I had that feeling when studying algorithm performance (with math proofs) and when studying the Scheme programming language (with all the fun stuff : call/cc, tunks, curification, CPS, immutability, pure function, lazy evaluation,...) This + my hands-on knowledge made me a very enlightened dev :-)

I had a much easier time in theory than the other students as well, and ended up being the only non-graduate level student in Quantum Computing, and only CS major in another, Combinatorics. I think a big part of it was that I had a strong maths background, graduating as I did from a Math/Sciences magnet school.

I had the same background of having gone to math/science/CS magnet programs in grades 6-12, which also helped me with the theory courses. Not to the same extent as my programming experience helped with the practical courses, though; theory wasn't something I did outside of school for fun.