http://www.catb.org/esr/writings/unix-koans/gui-programmer.html
One evening, Master Foo and Nubi attended a gathering of programmers who had met to learn from each other. One of the programmers asked Nubi to what school he and his master belonged. Upon being told they were followers of the Great Way of Unix, the programmer grew scornful.
“The command-line tools of Unix are crude and backward,” he scoffed. “Modern, properly designed operating systems do everything through a graphical user interface.”
Master Foo said nothing, but pointed at the moon. A nearby dog began to bark at the master's hand.
“I don't understand you!” said the programmer.
Master Foo remained silent, and pointed at an image of the Buddha. Then he pointed at a window.
“What are you trying to tell me?” asked the programmer.
Master Foo pointed at the programmer's head. Then he pointed at a rock.
“Why can't you make yourself clear?” demanded the programmer.
Master Foo frowned thoughtfully, tapped the programmer twice on the nose, and dropped him in a nearby trashcan.
As the programmer was attempting to extricate himself from the garbage, the dog wandered over and piddled on him.
At that moment, the programmer achieved enlightenment.