[A good teacher] explains step by step. Some teachers skip things. For example, if
you don’t understand a teacher, when subjects are closely linked, like Integral Calculus
and Differential Calculus, and if the teacher does not know how to teach it and you use it
to integrate. Sometimes, the teacher doesn’t want to explain, because he has already done
it, but even if you have already studied it, the teacher can go over it again so that you can
completely absorb what you have learned.