String and knot joke

A piece of string walked into a bar and said, "Give me a beer!"

But the bartender said, "Get outta here! We don't serve your kind here!"

So the string left, but he was thirsty, and he really wanted a beer, so he messed up his hair real badly and looped himself around until he had tied himself into a knot.

When the string went back into the bar, the bartender looked at him suspiciously and said, "Aren't you that worthless piece of string I just threw outta here?"

"No", the string replied, "I'm a frayed knot!"