This is so hard to set down in a manner that is believable. There are some explanations that simply do not make any sense to me. When someone says that it means something and yet the characters/ideograms don't necessarily support that something then you wonder what is used to back that meaning. Simply saying that someone said that Tatsuo-san told them it means that and to have others used as validation when the overall meaning is still foggy and lacking with emphasis that one must believe simply because the person said it was so seems implausible, to say the least.
My efforts to bring meaning to the characters/ideograms of the ken-po goku-i are based on personal training and practice along with studies of those ancient classics from China. I give a bit of credence to those studies from the sparse information that Tatsuo-san was a fortune teller who used the ancient Chinese classics for that endeavor. It connects but is not provable by more concrete means other than hearsay, etc.
When I read some explanations I find the explanations incomplete and a bit incoherent, like an ranting of belief that may be true for the individual but not connected solidly with Tatsuo-san. I am not saying that those persons are wrong. I am saying from a perspective that is different the explanations seem flaccid.
I also will admit that the characters/ideograms and their direct and indirect meaning are open to interpretations even if you give credence to what is stated as from Tatsuo-san. The parts as stand alone do connect to belief and meaning from the classics but as a whole tend to be loosely connected. The mere fact that my post is iffy at best adds to the credence of the ambiguity of the gokui - at best.
My rendition of what I attach to the gokui is mine alone. It may or may not reflect the intent of Tatsuo-san for his absence makes that impossible. He changed constantly and who knows what he may or may not have deduced from his studies of the gokui if he were alive today. Then again he may or may not have given any more to the gokui then most of what is given today as the meaning.
It is also possible that I give it more meaning than it is actually intended. I may attach more to it than Tatsuo-san would attach. It may be very simple indeed but then again it may not.
When you speak of Heaven, Earth and Man as part of the meaning then you find connections as to the culture and beliefs of early China when the I Ching and other classics were written, for those times and places along with the culture and belief of those who believed, lived and wrote the classics.
In the end it is a journey of the individual. Karate is a journey of the individual. Martial systems are a journey of the individual and the individual must arrive at a meaning the is true of that individual. Who is to say that it is either right or wrong and maybe in the end all Tatsuo-san wanted was each individual to think, study and contemplate all the possibilities only restricted by the culture, belief and practice of that individual.
Even the disjoined and sometimes vague interpretations I encounter today may be similar in context as the gokui itself. The meanings all have some connection to the ancient Chinese classics simply as "Heaven, Earth and Man" as related to the hexagrams/trigrams of the I Ching. Where we go with it is up to us and maybe that individual journey is all that is needed.