POV piece I wrote back in November 2003 to test out Amon's voice. Spoilers are actually quite mild, but do come from late in the manga.
His power isn't something he can turn off. He isn't as dangerous when he's in good health, but he knows there will be more battles on this journey, and even when he isn't using his power deliberately, how many years might he be subtracting from the lives of the people near him?
If he were the noble, self-sacrificing type, he would stay far away from other people, and he's tried it before. But he couldn't refuse Shido's request, and it seems he's too selfish, after all, to walk away from an infectious grin, from a man who so stubbornly refuses to leave him alone even knowing the risk.
It's been a long time since he's smiled like this. It's been a long time since he's had so much to smile about. He'll just be selfish for a little while longer, and give himself a little more to smile about after they've parted.