Answer:
There is one word that stands the test of time and holds fast to the center of everything. Though everyone will try at least once in their life to move around this word, but in fact, unknowingly, they use it every moment of the day. Young or old, awake or in sleep, human or animal, this word stands fast. It belongs to everyone, to all living things, but no one can master it. The word is?
Used left or right, I get to travel over cobblestone or gravel. Used up, I vie for sweet success, used down, I cause men great duress.
What can burn the eyes, sting the mouth, yet be consumed?
What can be heard and caught but never seen?
I usually wear a yellow coat. I usually have a dark head. I make marks wherever I go.
What gets broken if it’s not kept?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?