MY TWO CENTS: Perhaps a better question would be, why is sports so appealing?  There is a significant percentage of humans that are drawn to sports, not just watching, but actively participating. Some claim that the adrenaline rush is what motivates them, while others claim the calming effect of some sports to be what appeals to them.  Still there is a certain percentage of people who live vicariously through the experiences of an athlete/team.  Are some people born with a gene that predisposes them to sports? Or do we develop a love of sports from our experiences?  I am inclined to believe that there is a genetic component that predisposes one to either loving sports as a spectator or as a participant.  I had no experiences as a child; yet, I have been fascinated with sports or rather athletic endeavors from a very early age.  Perhaps it’s not sport per se, but rather a competitive personality that draws many people to sports.  It’s one venue that allows you to express your competitive nature.  The appeal of tennis and all individual sports is that you and you alone are pitted against the opposition.  Whether you win or lose depends solely on your ability to adapt or adjust to your environment/opponents. It can be eye-opening and humbling experience when you are bested by your opponent; however, those losses can be powerful motivating factors in your maturation as an athlete if viewed from the correct perspective.  You grow more from your losses than you do from your victories, because you are forced to examine more closely why you lost.