It's at night; when he thinks. At night when, as far as he can tell, the world is still and quiet and dark. Maybe not the whole world, but enough for him to feel comfortable enough to think. Reflect, remember, wonder. Any or all of those, it doesn't really matter.
He thinks about how things are. How they are now. How they used to be. He thinks about how he could have changed things, even the slightest bit. About how sure he is what they are doing is right; about if what he's done is right. He thinks about what other people think, of them, of him, of anything. He thinks about what he should be doing and what should have been done. And about the things that have been accomplished before the day was through. He thinks about things he's learned, and how to use that knowledge. He thinks about the constant danger. About what happens when someone dies. He thinks about not thinking, just going to sleep.
He wonders...how things could have been. How all this could have been prevented. What it would be like if they had succeeded. If he would have come home; come home and kept her from dying. If he hadn't made the suggestion; hadn't been so intent on it. Hadn't thought so highly of himself at 10. He wonders how things would be if the Colonel hadn't come that night; hadn't said those things. Would he have thought to do this on his own? He wonders what he would have done if he had failed the test. Would he have tried again? He wonders what would happen if tomorrow they found what they were looking for. If he died. If he gave up. If he knew, without a doubt, that what they were trying to accomplish was impossible; if it was for certain. And what would happen when it was all over. What would they do then? Would he leave his title behind? He wonders, even, how his brother really feels. He wonders what it would be like not to dream. Would he forget what he's done?
He remembers how things used to be. He remembers being young, naive, carefree. Trusting, genuinely hopeful, innocent. He remembers playing tag in the fields; being chased by the farmers. He remembers the first time he drew one of those circles and made something appear; helping his brother when he couldn't get it quite right. He remembers his mother's smile. Her laugh. The way she seemed to be able to fix anything; make all their problems go away. How she made him feel safe. How she looked the day she died. How she looked the day after that; how things had gone so wrong. He remembers how he didn't understand why things had happened that way. How much it hurt. How scared he was. How desperate. He remembers their house; before and after. He remembers the train rides, the confrontations, the trials. He remembers everyone he's met along the way; how he's helped them or hurt them. Or let them down. He remembers peaceful nights and skies full of stars. He remembers how he used to be.
It's during the day, when the sun rises, that he decides not to think anymore. No reflection. No remembering. No wondering. During the day when he's sure he's right. Sure that no matter what happens, things will turn out for the best in the end. No matter what that means. He's sure. Just as sure as his brother is in his faith in him; everyone's faith in him, no matter how little there is. And he decides that he'll do his best to not let them down, to not let their faith be misplaced. That, right then, nothing else matters.