"perhaps even the moment [Hassan] had been conceived in Sanaubar’s unwelcoming womb"

This quote paints an image of Hassan as an embryo, who is powerless to change the fate that is decided for him. Even as he grows up, Hassan doesn't have the chance to receive the kind of education that can allow him to change his fate, which means Hassan has no way to become anything more than a servant. This demonstrates how people in Afghanistan are born into the social classes that they live in. Moreover, the tone that Amir has used to say this quote with gives a sense of how rigid the class structure in Afghanistan is. The matter-of-fact tone that Amir takes on shows that it is a common understanding among the Afghans that most Hazaras will be born illiterate. By saying "the moment [Hassan] had been conceived," Amir also reveals that most people's futures are already decided even before they are born into this world. To have his future decided so early in his life, Hassan has no choice but to be a servant, just like Ali.