Real wisdom is not the knowledge of everything, but the knowledge of which things in life are necessary, which are less necessary, and which are completely unnecessary to know.
No matter how much we learn, there is always more knowledge to be gained. In this connection I am reminded of a short poem that has been in my mind over the years. It reads as follow: I used to think I knew I knew. But now I must confess. The more I know I know I know I know I know the less.