Orson Scott Card said this quote
“ Graff had isolated Ender to make him struggle. To make him prove, not that he was competent, but that he was far better than everyone else. That was the only way he could win respect and friendship. It made him a better soldier then he would ever have been otherwise. It also made him lonely, afraid, angry, untrusting. And maybe those traits, too, made him a better soldier. ”