A string walks into a bar and orders a beer. The bartender says, "Sorry pal, we don't serve strings here."

So the string walks outside, ties himself in a loop and messes up the top of his hair. He walks back into the bar and orders a beer.

The bartender squints at him and says, "Hey, aren't you a string?"

The string says, "Nope, I'm a frayed knot."