I'm a layman in terms of aviation, but I (and I'm sure many more do) do see aviation as a strictly regulated area full of double-checks, double instruments (even 2 pilots!) to make sure an airplane is doing exactly what it's supposed to be doing.
Perhaps mine is a rather car-centric view, but I can't imagine starting the engine of the car without knowing clearly where I'm heading, which landmarks, roads (and so on) I'm supposed to pass by during the route.
Must (or should) both pilots know where he airplane they are flying is going to? Or do they simply follow an approved flight path?