When to rest.

A crow was sitting on a tree, doing nothing all day.
A small rabbit saw the crow, and asked him, "Can I also sit like you and do nothing all day long?"

The crow answered: "Sure, why not."
So, the rabbit sat on the ground below the crow, and rested. All of a sudden a fox appeared, jumped on the rabbit and ate it.

Moral of the story:
To be sitting and doing nothing, you must be sitting very, very high up.