Throughout the book, characters, especially Ender and Graff, must make personal sacrifices for humanity’s survival—and many of those choices impact the people they know and love. First, Ender sacrifices companionship with his family and Battle School students. Though Ender consents to Battle School and plays the adults’ game, he doesn’t necessarily choose this sacrifice for himself. Graff coordinates Ender’s isolation to prepare him for the commander position: “His isolation can’t be broken. He can never come to believe that anybody will ever help him out, ever. If he once thinks there’s an easy way out, he’s wrecked. [...] He can have friends. It’s parents he can’t have” (28). However, the measures Graff takes deprives Ender of opportunities to sustain any meaningful connections. Because he must constantly strive for perfection, he takes every moment of training seriously, which means he can’t relax and joke with his friends; even when he wants to, he doesn’t know how. For example, after his friends have an amiable moment together in front of him, Ender describes, “They apologized again. Back to business. Back to respect. […] How could they think I was part of it? Did I laugh? Did I join in? Just stood there, watching, like a teacher” (99).