Answer:
If you have it, you want to share it. If you share it, you don't have it.
Runs smoother than any rhyme, loves to fall but cannot climb!
What is it that no man ever yet did see, which never was, but always is to be?
It's equally comfortable in an orchestra and a geometry textbook. What is it?
What has a head, a tail, is brown, and has no legs?
When is it bad luck to see a black cat?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?