In chapter 16, Amir has an enlightening conversation with Rahim Khan regarding Hassan's life as an adult. Rahim Khan tells Amir that Hassan and his wife came to live with him at Baba's estate. One day Sanaubar, Hassan's mother, knocked on the door. Rahim Khan recalls that Sanaubar looked like she hadn't eaten for days and had lacerations across her face. After initially seeing his mother, Hassan ran away from Baba's home and didn't return until the next morning. When Hassan returned, he nursed his mother back to health and began to repair their lost relationship. Rahim Khan tells Amir,
They [Hassan and Sanaubar] were catching up on all the lost years, I suppose. As far as I know, he never asked where she had been or why she had left and she never told. I guess some stories do not need telling (Hosseini, 180).
Rahim Khan's comment reveals that there is no evidence to suggest that Hassan feels guilty for his mother leaving. Judging by his immediate reaction to her reappearance, Hassan was upset that his mother left, but there is no evidence to suggest he feels guilty for her departure. If Hassan felt guilty about his mother leaving, he would have probably asked Sanaubar if he was the reason she left their family.