This is a great question, as chapter 11 is somewhat of a turning point. In this chapter, two thing events stand out. Baba, who is now in Fremont, California and works at a gas station, goes to buy something at the local store. He goes to pay by check and the store attendant wants an ID. Baba is furious and overturns a magaine rack. He feels insulted, not knowing that this was people do in America. More importantly, he feel frustrated at his new life. Back in Kabul, he was a powerful and respected man.
As one can see he is having a hard time adjusting to life in America, but he presses on. Why? The text explains that he does it for Amir, his son. He wants a better life for his son. This show Baba's love and sacrifice.
The other scene is when Amir tells Baba that he wants to be a writer and studing English in college. Baba is not happy and says that the degree would be useless. However, later on when Baba has a meeting with general Taheri, he tells the general that his son will be a great writer some day. This show Baba's heart for Amir. He might disagree with Amir's decision, but he loves him and will support him.
In many ways, this dynamic can be seen in this quote: "For me, America was a place to bury my memories. For Baba, a place to mourn his." Amir looks towards the future; Baba is haunted by the past.