Answer:
I am used when you jump off a bridge for fun.
I am always around you but often forgotten. I am pure and clean most of the time, but occasionally rotten. What am I?
I can bring tears to your eyes, resurrect the dead, make you smile, and reverse time. I form in an instant, but I last a lifetime. What am I?
I hide but my head is outside. What am I?
Of these things - I have two. One for me - and one for you. And when you ask about the price I simply smile and nod twice.
It's what light turns into in the night