A farmer and his dog used to sit by roadside waiting for vehicles to come around. As soon as any vehicle came, farmer's dog would run behind it down the road, barking and trying to overtake it. Farmer neighbor used to see this and one day out of curiosity he asked farmer, "Do you think your dog is ever going to catch a car?"Farmer replied, "That's not what I am bothered about. what bothers me is what would he do if he ever caught one?" 
Many people in life behave same way pursuing meaningless goals. 