I love this

These are the first few lines from a poem written by Alexander Pope.  It's called "Essay on Criticism" and it cautions us against learning a little bit and thinking we know a whole lot.  I don't know if anyone else will dig this.  (ps- the Pierian spring was the mythological source of knowledge, and this picture is not it.)

A little learning is a dang'rous thing;

Drink deep, or taste not the Pierian spring:

There shallow draughts intoxicate the brain,

And drinking largely sobers us again.