Yeah, I remember reading online and thinking that this stuff, "IT", was close to what I was doing or had done. But, as someone else has said, "I didn't know that I didn't know". "IT" wasn't even close to what I was doing or had done. And the IT I'm doing now isn't even close to what I had used for training methodology before.
I was watching a video the other night of a fairly good Xingyi practitioner (to use and example that no one in Aikido will feel offended by) and he had pretty good I.S. power, obviously. I've heard that this man is a very good fighter and can seriously kick butt. But I could see how he developed his power and used it in most cases.
The levels of internal power can be equated to Shu-Ha-Ri in many Chinese arts, where they say: Obvious Power, Concealed Power, and Mysterious Power. Of course a person who only uses normal strength (even one who can fight well) is not even in the categorization. The man I watched was very strong, but he was more or less someone with a combination of obvious and concealed power; not mysterious power.
My point that I'm slowly working toward is that a person with no I.S. skills can't really conceive of I.S. skills.... he only knows what his own abilities allow him to grasp. Similarly, a person developing I.S. skills only truly understands from within his personal skills and the grasp of higher skills can be equally blinded from below. A person does not "know I.S."... he only knows up to the level that he can do. Hence Ueshiba was not just talking idly when he discussed how long his journey had been.