They really don't have to know much about anything except how to program the computer to get them from point A to point B.
I'm 24 and fly the Airbus for a living - does that make me one of the 'kids' to whom you refer? I find that post a little condescending to be honest. Why did I bother spending 2 1/2 years training - and still learning from my experiences all the time - when I could have just used Flight Sim to teach me to programme a box? Wish I'd thought of that...
That is to say, on a Flight Sim with joystick and keyboard. So, while I don't have as many hours on the sim as in real aircraft, I do have a little "feel" for FBW.
Are you seriously suggesting that spending a few hours on FS gives you the feel for FBW, or even comes close to replicating the handling characteristics of the real aeroplane?!