In a very real sense, these outer planets’ cycles are of a duration longer than an average lifetime. For sure, the 84-year cycle of Uranus is now within range of the average lifespan, at least here in the West, but that was not necessarily true when it was discovered. Neptune and Pluto’s orbits are, of course, well beyond any one person’s lifetime. We don’t personally live that long.
This fact, itself, is of interest. We could say as fact that a single person will not manage to encompass all the degrees of the zodiac these outer planets cover within their personal experience in a lifetime, and that, because of that, in a real sense we do not and cannot personally “know” the whole nature of these planets.
I suggest that this may very well be why there are groups, brotherhoods, and lineages of an esoteric nature. Some of this information, which we cannot experience ourselves, may be passed on from mouth to ear, above ground so to speak, and may not travel through the womb-birth process. This is pure speculation on my part, but something that makes a certain amount of sense. Does it not? There are indeed many whispered stories of what is beyond life.