Home is anywhere that you know all your friends and all your enemies.

Personal affection is a luxury you can have only after all your enemies are eliminated. Until then, everyone you love is a hostage, sapping your courage and corrupting your judgment.

I would carry some of it if I could, Bean said silently. Like I did today, you can turn it over to me and I’ll do it, if I can. You don’t have to do this alone.

Only even as he thought this, Bean knew it wasn’t true. If it could be done, Ender was the one who would have to do it. All those months when Bean refused to see Ender, hid from him, it was because he couldn’t bear to face the fact that Ender was what Bean only wished to be — the kind of person on whom you could put all your hopes, who could carry all your fears, and he would not let you down, would not betray you.

I want to be the kind of boy you are, thought Bean. But I don’t want to go through what you’ve been through to get there.

Thanks from keeping me from being a liar," said Nikolai.
"What?"
"About your having diarrhea."
"For you I'd get dysentery."
"Now that's friendship.

Home was merely a dull ache in the back of his memory. A tiredness in his eyes.

An enemy, Ender Wiggin," whispered the old man. "I am your enemy, the first one you've ever had who was smarter than you. There is no teacher but the enemy. No one but the enemy will tell you what the enemy is going to do. No one but the enemy will ever teach you how to destroy and conquer. Only the enemy shows you where you are weak. Only the enemy tells you where he is strong. And the rules of the game are what you can do to him and what you can stop him from doing to you. I am your enemy from now on. From now on I am your teacher.