We all have some skills that are fully associative and natural, and some that require active focus.

For me, proprioception requires my forebrain being fully active, but planning doesn't.

With tons of practice you can shift from active focus to intuitive, but our individual rates of learning for different skills are different.

Presumably it's possible to only optimize for a few skills that are intuitive, and not have much more space to cram things in over time.

That's why "you can't teach a dog new tricks."

The tricks you learned intuitively earlier in your life were the ones you worked hard enough on before other skills.

They were likely the ones you had a natural advantage at, so they were more fun, and it pulled you through the slog of learning.