Figuring out what needs to be declared is the tricky part.

Back pre-GE, I always declared everything acquired abroad down to "misc papers $0;" even then it was never clear that non-scheduled prescription drugs that left the US with me and were coming back in were supposed to be declared and when asked specifically about prescription drugs "nothing acquired abroad" was accepted.

With GE, given the way the questions have been phrased on the machine and how we were told to arrive in the past, it's not even clear how you declare things without skipping the machine and going to an immigration agent -- which is what I've done when I've come back with questionable food products.