*based on Ross Scott's "Freeman's Mind"

Shephard is finally given an actual field mission to partake in, but he's pretty convinced its still just another training mission. Weather its real or not, Shephard goes about it as if it was fake so as to keep himself moving forward. He doesnt believe himself to be ready for any actual field missions, and so maintaining the preconcieved notion of unreality keeps him from going completely insane. So assuming its all fake, he runs into a few fellow soldiers and scientists, and a particuarly heavy set security guard who decides to help him under the condition that Shephard help back.
Shephard is still in a daze from the well coreographed helicopter crash and the overwhelmingly realistic make-up and set pieces. They really help to give the illusion of reality, but its all fake. Right?