Brain Missing is one of the Collectibles in the AWE expansion of Control.
File text
To the good-for-nothings at the security check,
I know you took a part of my brain when you put me through that "metal detector", I'm not stupid. I know what they're really for. What I don't know is whether taking a part of my brain causes me to lose my memories or to lose sleep. I've been told if you lose sleep you lose everything else too. That's where you trick us regular people. Now I don't know which it is and I can't remember what you did to me!
But I can tell you this much, I don't find this funny at all! I want my memories back, and you can be sure the next time I visit the Baltimore-Washington International Thurgood Marshall Airport, I will come and find you and make you fix what you broke!
Sincerely,
I don't think I will be signing this with my real name. Like I said, I'm not stupid. You can just mind your own business!
Location
The file can be found in the Investigations Sector, in the Utility Corridor. It is in the room just above the Turntable, accessible by either backtracking through the Utility Corridor or starting from the Turntable Control Point and Levitating up to the elevated window.