Answer:
A mile from end to end, yet as close to as a friend. A precious commodity, freely given. Seen on the dead and on the living. Found on the rich, poor, short and tall, but shared among children most of all.
I hide but my head is outside.
There is a puzzle which can be asked all day with a different correct answer each time. What is the puzzle?
Runs smoother than any rhyme, loves to fall but cannot climb!
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
What never gets any wetter no matter how hard it rains?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?