We can try to understand about how brain really learns by realization of the fact about how we learn languages.
Its pretty evident, that one does not learn langauges by grammar, and sequential instruction with a list of words and meanings.
That is a very slow and obstrusive way of learning a language.
I was born and grew up in India, where learning English was seen as very important for stable future career.
English was taught in all schools, but only children who got practicing environment outside of classroom learnt better spoken and written English.
I was lucky few, who had access to English songs, TV, and books. So my English got better, when is started doing self reading.
But it took me a very long time in learning English as it did for hindi. Because we used that language right away in our LIFE.
But school system takes a very mechanical way of teaching a language. And much of this is about taking away flexibility.
A brain wants to jump from one topic to another, fast, want to repeat one topic more than another. Needs long breaks and sometimes long continuous immersions. It needs various stimulas, contexts, reminders, repetition in order to grasp any knowledge and skill set.
Context and use/reward
Stimulus, environment and guides
Schools can be a great place to learn if FLEXIBILITY is provided there. And to do that, we will have to do away with CLASSROOMS, fixed syllabus, strict schedule and assessment methodology.