A piece of string walks into a bar. The bartender says, "sorry pal, we don't serve string here, you have to leave."

The string leaves and rounds the corner but then he thinks, "I really want a drink" so he gets an idea. He twists and wraps himself up and messes up his hair, and then he walks back into the bar.

The bartender looks over and says "hey, aren't you that same piece of string I just threw out of here 5 minutes ago?"

The string looks at the bartender and says "nah, I'm afraid not (a frayed knot)."