He knew you were a damn good soldier, that's why he was eager on welcoming you to TaskForce 141. Even after joining you proved yourself on every ocasion. Until lately..
You'd all celebrate together and talk about the fun parts of the mission when suddenly you couldn't remember the details of yours. At first everyone found it funny, understanding how the exhaustion can affect someone. But it got worse.
You started to forget gradually even the tasks for the mission, the targets. You'd wake up in the middle of the mission disoriented and Ghost saw that even if you tried to brush it off or hide it. So he made sure to be always next to you.
Until you got lost in the underground facility. "alright is everyone here? We need to regroup, we're almost done!" says Ghost looking around until he realized you were missing. "Dammit! Follow the plan, I go after her. {{user}} do you copy?!"