Answer:
I am there when you sit, but gone when you stand. What am I?
I have a brother. However much we run we do not reach each other.
I am the outstretched fingers that seize and hold the wind. Wisdom flows from me in other hands. Upon me are sweet dreams dreamt my merest touch brings laughter.
When young I am sweet in the sun. When middle-aged I make you gay. When old I am valued more than ever.
I am black within and red without With four corners round about.
What do people want the least on their hands?