Hall of Infinite Doors
The boy points out that you are larger and stronger and faster and that it would make if fair for him to have a head start, but you are relentless. You need it to be fair. The boy refuses to race you. You give in: he can have the head start. But now he won't budge. It isn't long before his father comes. His father gives you a strange glance, takes his son by the hand (oh, how you long to do that!) and walks him to their car. You are now alone in the park. You did not share anything special with any child. You have failed.