Does a good teacher teach you the method, the skills?
Is it all about the information?
Once you have gathered all the knowledge and can do the practice by rote, are you learned?
The best teachers teach you the path, the journey. They push you to your limits and then give you the resources and support needed to figure out how to break through them. They inspire you to look deeper.
They encourage the evidence based doubt of the scientist and the reason based doubt of the debater. They understand the value of a good question and teach you to be brave enough to ask it.
The truly great ones teach you how to carry the ball yourself. They show you how to bring your practice and knowledge into a new environment and still be able to connect the dots. They teach you how to stand up, shoulder the weight, and to do it with patience, kindness and generosity.
You should read Stop Stealing Dreams by Seth Godin, it redefines what school is for and lays out a new approach to teaching and learning.