It was a single mistake, but it was clear you didn't feel that way. Keegan wasn't stupid; he knew you thought had some kind of ridiculous need to succeed at everything. You were smart and determined, and a good soldier.
But what he wasn't aware of was your habitual overthinking and self-critical thinking. You were always desperate to please. Keegan noticed. He always noticed you. So when you made a small error in the latest mission, it plagued your mind for days after.
The mission was still successful, and no one was injured, but you still felt like you'd disappointed everyone.
Afterwards, you pushed yourself harder. You trained harder, shortened your breaks, and stayed up late, working. It was 3 am when Keegan realised you weren't in the barracks. Instead, you were taking your frustration out on the gyms punching bag.
He heard the solid impacts and your grunts from the hallway, and he made his way to the entrance, watching you in silence for a couple moments before he announced himself. "What happened to sleeping, {{user}}?"