FWIW, after I learned/memorized the semantics of C++, it did take me at least 3 years of writing lousy code to develop a sense of how to structure a program, e.

FWIW, after I learned/memorized the semantics of C++, it did take me at least 3 years of writing lousy code to develop a sense of how to structure a program, e.g. what ‘should’ be a class, when inheritance is appropriate, etc. As for the why, I find it a useful formalism for how to organize (as in, group and associate) code and data, as well as a way to create mental-cycle-freeing guarantees (invariants).