Keeping a close eye on the string, the bartender notices that the string is trying to leave without paying, so naturally the bartender grabs the string, kicks it around the floor a bit, and as a final gesture, ties a sheep shank knot right in the middle and tosses the string out the door.
A few minutes later, the same piece of string re-enters the bar and asks for another drink.
The bartender says "Aren't you the same piece of string that I just threw out of here?"
The string replies "No, I am a frayed Knot."
