The point of taking lessons is not so much that you will learn in a linear manner from one lesson to the next, but that you will find yourself open to change because you will have put yourself in a position to welcome it should it occur.
It is a particular kind of ritual.
However, it does depend on the openness of the teacher, as well as your openness as a learner - aren't we all learning all the time? Ah! There's the rub.
Classical music has too long been associated with a "been there, done that" mentality that leaves no room for change.
That is not at all where I stand or how I practice either teaching or learning.