Answer:
It holds most knowledge that has ever been said. But is not the brain, is not the head. To feathers and their masters, it's both bane and boonΒ One empty, and one full.
What has wings, but can not fly. Is enclosed, but can outside also lie. Can open itself up, or close itself away. Is the place of kings and queens and doggerel of every means. What is it upon which I stand? Which can lead us to different lands.
An open ended barrel, it is shaped like a hive. It is filled with the flesh, and the flesh is alive!
What has three ways out and just one way in?
What comes once in a minute, twice in a moment, but never in a thousand years?
You use it between your head and your toes, the more it works the thinner it grows.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?