People actually get the feeling and the understanding when they just "do aikido",
I think I understand you here, but I'm not in full agreement, especially about the "gets old" - what I've noticed is that often people feel they understand a technique when they are comfortable executing it and and happy in their stance and movement. This is not always the same thing as being correct and balanced and a verbal clue can help us much more than constant repitition.
Mary's example was a nice case in point. For me a nice wide balanced stance all the way throughout happo-undo just doesn't fit my top ten comfortable stances, but what is comfortable and feels right just isn't and all it took was a single phrase (neck down - I'm a short-arse so over-compensate) to correct this during the revision.