What symbolism within the novel shows how the past affects the present?

Kites are a constant motif throughout the book. The kite represents Amir's shameful past. He will always remember the blue kite falling when he failed to protect Hassan from rape. Kites also represent the future and at least some redemption. We see this in the last seen of the book when Amir is flying the kite with Sohrab, Hassan's son, in America.