Huh. I have to say, my experience is more that the teacher says "X! Do X!" and then months later I realize, "Damn! It works if I just do X! Why didn't anyone tell me that?"
I think this is very true, but unless you are some kind of prodigy it takes a lot of training before you can "just do X". For instance, when Ikeda Sensei says "move partner's tailbone", most people in the class think "what the hell?", but I am just getting to a stage where I kind of understand what this involves - not that I can do it reliably with an arbitrary partner.
In the same way, Kanetsuka Sensei has said "cut partner's knees": I am now getting an inkling of how this is even possible when the partner is holding you by the arm. When he does shihonage on me I can feel that he is doing just this - with anyone else, my arm starts to move first, but with him my feet move first. In this case I can now see that the best way to accomplish this is simply to "cut partner's knees".
I think this is similar to Michelangelo's famous statement about starting with a block of marble and being able to see the horse inside it that he will eventually carve, and then chipping away "everything that is not horse".