Again for the general readership, not a criticism of any one individual's approach, this process is like a job interview.
I recently interviewed at Under Armour. They have a mission (yes, it is Protect This House, but also more), but when asked what I knew of their mission, I didn't recite it back to them. They already know the mission. I knew they wanted my answer to express understanding of the mission, so I used elements of the mission to draw connections to my own experience. That demonstrated I had done my homework, had thought about what it meant, and related it to my potential and competencies. It's an essay question, a thought piece, not a test question with one answer.
Learning the mission at NASS is designed to give a taste of some of the rote memorization drills required in military life. Yes, it does create awareness of the mission, but the candidate has to do some thinking about what that means and how they are cut out to deliver on their end.
An interview during the EAs application process is a very grown-up conversation, exploring motivation, potential fit, skills, aptitude, understanding. It is, in every sense, a job interview.
My .02!