I never got too into C where I heavily used macros. I've seen some magic in C where you define function tables for objects and recreate object oriented programming but to be frank it's painful mimicry as well here. The best mixin I've seen is where you use function pointers to help de-duplicate code.

I would say C taught and learned correctly can teach you the memory model computers use and the concept of pointers. Other languages do other things better, like Java can teach you about memory management via garbage collection and references.