People are incredulous when I tell them I use 90% of the stuff learned while getting my CS degree.

Stuff I've done in the real world:

AI: I've lost count of the number of times I've had to implement A*

Graphics: wrote a ray tracer; matrix transformations

Data structures and algorithms: wrote an approximation algorithm for the travelling salesman problem (christofides); fancier data structures like bloom-filters, lru caches; and just every day coding

Databases: query optimization

OS: Made me aware of systems (context switching, caching performance,...). Scheduling algorithms and how they affect the embedded software I write. Concurrent programming.

Networking: Super helpful for everyday stuff when you understand the underlying principles. I've had to implement an RFC from scratch (DNS).

Linear algebra: Used extensively in a path planner I wrote---with it I was able to reduce the state space by orders of magnitude compared to the standard grid approach.

Statistics: wrote an online algorithm for adaptive windowed linear regression

Even computability theory has been helpful, as it has strengthened my proving and reasoning skills---helping me find holes in requirements, or proving algorithms/invariants. Same with all the theoretical math courses I took (Analysis, Set Theory, First Order Logic ...)

The list goes on...

Above all, my CS degree taught me how to learn CS and beyond.

Sometimes I worry about the potential solutions I am overlooking, because I never fully branched into the continuous domain (control theory, etc).