"Butterflies are funny. Some days they make you run to the toilet. Other days they make you horny. Other days they make you laugh, and long for the fight. Deciding which type of butterflies you’ve got going (monarchs or moths) is the first order of business when you’re driving to the arena. Figuring our your butterflies, deciphering what they say about the status of your mind and body, is the first step to making them work for you."

Andre Agassi played tennis professionally from 1986 to 2006. Often ranked number 1, he captured eight Grand Slam singles championships.