Answer:
What has a head, a tail, is brown, and has no legs?
This is in a realm of true and in a realm false, but you experience me as you turn and toss.
Not born, but from a Mother's body drawn. I hang until half of me is gone. I sleep in a cave until I grow old. Then valued for my hardened gold.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?
I repeat only the last word you say. The more I repeat, the softer I got. I cannot be seen but can be heard. What am I?