You might notice that the novel begins with a very particular flashback, Amir hiding behind a "crumbling mud wall" (1), looking into an alley. He tells us that "I became what I am today" (1), in that moment, and that he has been "peeking into that deserted alley for the last twenty-six years" (1).
We, as readers, understand from the very first paragraph that this moment is central to Amir's entire life, up until the "today" in which he is an adult telling this story. The flashback provides foreshadowing, a hint that we will learn about what happened in that alley. It also, because of its descriptions, the words "crumbling,""mud," "frozen," and "claws," for example, foreshadows for us that whatever happened was not good, something so terrible that Amir has tried to "bury" it for 26 years.
We learn quite a bit about the narrator in just that one brief flashback. We learn that he is now 36, since we can add! We understand that he has tried to repress the memory of this alley, and we learn that he has not been successful in this attempt.
As the first chapter continues, the narrator's memories provide us with a bit more. We learn that the sight of kites triggers a memory of someone named Hassan, "the harelipped kite runner" (2), who has told Amir in the past that he would do anything for him. And finally, we learn from Amir's recollection of his conversation with Rahim Khan, that he has done something wrong in the past. What Rahim Khan says to him,"There is a way to be good again (2), is a major theme of the novel.
This is a brief first chapter, but it is quite well done because it sets the stage so beautifully, with an introduction of the two major characters, the scene that is central to the story, and a statement of a major theme of the novel.
Hosseini relies heavily on flashback not only to build suspense but also to support his theme of the past's immense effect upon the present. At the beginning, Hosseini begins the novel in present day and then flashes back to Amir's childhood. By using one-sentence statements such as "There is a way to be good again," the author causes the reader to want to keep reading to see what those statements suggest. The flashbacks then explain the significance of the statements.
Amir is haunted by the past--he cannot be completely happy in the present or future until he goes back to redeem himself for past actions.
In the story "The Kite Runner" the flashbacks serve a very significant purpose. Amir had never been able to surpass the experiences of his childhood following a day when he witnessed his friend/servant raped by Assef. The story begins with the day that it all had occurred so that the reader experiences foreshadowing of the events to come.
In the beginning the reader learns that Amir sets the tone for the story. He gives the reader a history of his father and the relationship of Afghanistans with the Hazar people in the country. We learn that they are not an accepted people and considered to be beneath others. We also learn of the relationship between Amir's father and Ali. We learn that Amir's feelings for Hassan, the Hazara child who he hangs with and who lives on his property is Ali's son. The first paragraph sets the stage for the others that follow.