Why do something that has already been done? Why do something in a difficult manner when there are shortcuts to take? Simple — the process itself is enjoyable, even if the goal is nonexistent. Being content with doing useless things is the greatest gift one can receive in life. To take pleasure in the mundane and the nonsensical is to have the power to redefine suffering and turmoil in your own terms.
Laugh at the face of the inevitable. One must imagine Sisyphus happy.