Understanding Somebody

How well do you think you understand your grandparents?
How well do you think you understand your parents?
How well do you think you understand your siblings?
How well do you think you understand your spouse?
How well do you think you understand your friends?
How well do you think you understand your children?
How well do you think you understand your grandchildren?
How well do you think you understand yourself?

If one needs a whole life time to trek through one's path of self-discovery to understand oneself, how can anyone expect another to understand oneself?

And some would even argue that at the end of the trek, one may not even have fully understood oneself.

If you agree with that, then how can anyone expect a teacher to understand 30 young creative and developing minds in a go???