Answer:
Through its wounds, water does run. It once held many but now has none. What is it?
What two things can always see what the other sees, but can never see each other?
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.
Whoever makes it, tells it not. Whoever takes it, knows it not. Whoever knows it, wants it not
Three little letters, a paradox to some. The worse that it is, the better it becomes.
You use it between your head and your toes, the more it works the thinner it grows.