Answer:
The man who invented it doesn't want it. The man who bought it doesn't need it. The man who needs it doesn't know it. What is it?
The sharp slim blade, that cuts the wind.
What can be heard and caught but never seen?
My first is a body of water. My second is me. My third came before. My fourth before all three. My fifth sounds like my first. My sixth is in a lake. Put all six together to make an animal that will keep you awake.
A precious stone, as clear as diamond. Seek it out while the sun's near the horizon. Though you can walk on water with its power, try to keep it, and it'll vanish in an hour.
A cowboy rode into Friday. He stayed in town for three days and rode back on friday. How is that possible?