The other one that got me was losing Cortana in Halo 4, I made it through her death, but that scene on the deck. When he says: "Our duty as soldier is to protect humanity. Whatever the cost."
Lasky: "You don't talk much, do you? (John does not respond.) Chief, I won't pretend to know how you feel. I've lost people I care about, but… never anything like you're going through."
John-117: "Our duty, as soldiers, is to protect humanity. Whatever the cost."
Lasky: "You say that like soldiers and humanity are two different things. Soldiers aren't machines. We're just people."
John-117: "She said that to me once. …about being a machine."
[ame="https://www.youtube.com/watch?v=0sZvDHeZQWw"]https://www.youtube.com/watch?v=0sZvDHeZQWw[/ame]