It is said : "From Special to General".
The meaning of this is as follows :
Firstly, we can learn only in the style of "from special to general".
Why "generalization" comes? It is not an issue about our tastes.
"Generalization" is one of methods which make knowledge useful as tools.
But, only those who are advanced understands this type of usefulness of tools. For beginners, a generalized form is just a noise. We must experience many things before the noise changes to an entity which has a meaning for us, that is, before we become able to understand its reanson for existing and usefulness.
And we "experience" only in the form of "from special to general".
Secondary, learning only works in the form of "generative understanding" (that is, "take little, then generate much as the occasion demands"). Learning of the form of "storing" ("memorizing") breaks down soon.
And "little" in this case means "generative special".
For example, for understanding "linear algebra" it suffices to understand "quantity" as the special. All seeds of "linear algebra" in high school mathematics are present in primaty school mathematics.
Remark : Do not understand "little" as a kind of "axiom".
But, it is not easy to practice "from special to general".
The "special" must be understood very flexibly. If not, we cannot proceed to the "general".
But we are inclined to be fixed to the "special".
Here, the ability of instructor, or instructor's justification for existence, is asked.