A piece of string walks into a pub and asks for a drink. But the bar manager refuses saying: "No way, you're just a piece of string."
So he ties himself up into a knot and frays his edges in the hopes that the barman will fall for his disguise. He walks back into the bar and asks again for a drink. The barman says again: "No way, you're just a piece of string."
But the piece of string replies: "I'm afraid not."