The chicken crosses the road, because if it didn't our world would be unbalanced. Children would never know the joy of asking each other "why did the chicken cross the road?" and answering with ludicrous answers such as "to be smashed by the building." Adults would never experience the misery of a joke without comedy that goes on far too long. And without that specific combination of joy and misery, the world would fall off its axis, propelling us all miserably through the deepest reaches of space.... or maybe just into the sun.
*** This post is in response to the question of the day at Seven Days, Seven Answers***