What happens as Amir runs the kite for Sohrab? How is this another full circle?

When Amir and Sohrab fight the blue kite, the story finally comes full circle. The sport takes Amir back to the moment before everything changed, when Hassan had not been raped and they were just two boys having fun together. He says, "I was twelve again." Now that Amir has forgiven himself, kite fighting reminds him of pleasure instead of pain. His memories no longer being painful, he shares them with Sohrab: "Did I ever tell you your father was the best kite runner in Wazir Akbar Khan? Maybe all of Kabul? ... Watch, Sohrab. I'm going to show you one of your father's favorite tricks, the old lift-and-dive." In the ultimate moment of circularity, Amir runs the kite for Sohrab just as Hassan ran his last kite for him half a century before. Finally Amir understands what it is like to be as loyal and loving as Hassan, and can truthfully repeat Hassan's words, "For you, a thousand times over." The kite is a symbol of Amir's good, fatherly wishes for Sohrab. He wants to bring him joy, opportunity, a sense of security, and the will to live again, if only this were as easy as bringing him the kite. The last time Amir went to find a kite, he ended up turning his back on Hassan for good by running away from the scene of his rape. This is why the novel's last words, "I ran," are so meaningful. Even though Amir's story has made a circle metaphorically speaking, it has not ended where it began. Amir is running in a positive way, away from Sohrab physically but toward him emotionally. He is finally running with freedom in his heart instead of fear.