If I recall correctly, this was the essence of Yossarian's bind in Joseph Heller's novel, Catch 22. If you love the adrenalin rush and are totally oblivious to danger, you're obviously crazy, and they won't let you fight. If you are greatly concerned about the possibility of getting your butt shot off, you're normal, and they ship you directly to the front lines.

That's the catch.

Don Firth