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 boon One empty, and one full.
Bold are the first; true are the second; playful are the third; clever are the fourth; forceful are the fifth.
All about the house, with his lady he dances, yet he always works, and never romances.
Talks like this, a green wise man does. Guess my clue, you will.
A man shot two arrows at its center and missed both times, but using a sword swung once at its center and hit it twice.
Dry though I may be, I am still a sea.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?