Train this monkey !"

"Imagine a room with five windows. There is a monkey in the middle of this room. This monkey is constantly jumping form one window to another, in order to communicate with the world outside. Train this monkey !"

Note:

This simile was originally taken from a Theragatha.
In this simile, the monkey is the mind (internal sense) and the five windows are the eyes, the ears, the nose, the tongue, and the body (external senses). Training the monkey is the practice of meditation.