Answer:
I am free for the taking. Through all of your life, though given but once at birth. I am less than nothing in weight, but will fell the strongest of you if held.
The more of it there is, the less you see.
What can be filled with empty hands?
Searing 'cross the pitch-black skies, I scream in celebration, Yet moments later, my outburst through, I am naught but imagination.
What bird can lift the heaviest weight?
What covers its face with its hands, speaks no language, yet most known what it's saying?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?