I've never been in the military, so I don't know how the selection process works, but I would hope in these times and with the technology available that a military personnel's function in the organization be determined like this.
I'm playing this game on facebook (Bejeweled Blitz) and suddenly I realized that the things I would have tried for if I had joined the military (Pilot) I probably wouldn't have gotten. What does this have to do with bejeweled? well, I realized the reason I have trouble getting a high score, is my inability to process large quantities of visual information quick enough to be able to react properly. In short, my situational awareness sucks! So there I'd be in a helicopter or jet fighter, and I wouldn't be able to react fast enough to save my skin or anyone else's! See, I also noticed this trend in other games that I've played, but some things I do better at than others. My brother on the other hand is better at situational strategy. My own strengths lie in thinking but I can't do it while stressed. I come up with broad ideas easily, but usually need other people to fill in the details. I'm also good at efficiency once I know all the variables involved and the goals that need to be accomplished.
Just playing games
So since a good determination of an individual's thought process and abilities can be determined by what games they are good at and enjoy, it only follows that part of the selection process include a "break-time" where the individuals have the opportunity to relax in a way that they choose, with a selection of games and activities available designed to help determine which tasks an individual are suited for... which are not always likely to be what the individual thinks they want.
Dreams in flames
For many people the reality is not what the dream was imagined to be. In my own previously mentioned example, I wanted to be a pilot. I would have flunked out on math most likely, although oddly enough I've since learned that all of troubles with math stem from the way I was taught to think about it, not an inability to do it. but even if my math was good, my brain is still not quick on it's feet, a bad thing for anyone required to make high speed, life or death decisions where one instant of hesitation can mean destruction. later on in life I discovered that I'm good at other things, and while I still enjoy playing those games that I'm not very good at, I at least realize that it would not have been for me had I gone that route.