"Maybe Hassan was the price I had to pay, the lamb I had to slay, to win Baba." (Hosseini 77)
"I finally had what I'd wanted all those years. Except now that I had it, I felt as empty as this unkept pool I was dangling my legs into." (Hosseini 85)
"That was when I understood the depth of the pain I had caused, the blackness of the grief I had brought onto everyone, that not even Ali's paralysed face could mask his sorrow."
This quote shows a big part of Amir; his jealousy, his inner struggle and how, in the end, he will sacrifice everything in order to form a bond with Baba.
This is important because he is starting to realize that what he did is not right, it's not making him happy. He is realizing that the friendship he had with Hassan made him happier than his friendship with Baba wich was built with lies and betrayal.
This shows how Amir's feelings affect and hurt the people around him. It also marks a turning point in the story. Where he actually admits and understands the power and pain his actions have caused.