Answer:
Kings and queens may cling to power and the jester's got his call. But as you may discover the common one outranks them all. What am I?
Can not be bought, Can not be sold, Even if it's made of gold. What is it?
What gets sharper the more you use it?
I am always around you but often forgotten. I am pure and clean most time but occasionally rotten.
I row quickly with four oars but never comes out from under my own roof.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.