The idea is that there's more to learning (knowledge) than filling up one's container. Learning is not a quantitative measure but a qualitative one that relates to how the mind is organized. Each new step requires a transformation of this organization.
I'm talking about something different than someone saying that a fish is a vegetable.
For example: When playing cards, you probably don't count the number of spades on a card. Rather you see the pattern and instantly recognize it as 8 of spades or 5 of spades. You can play cards perfectly well without having an conceptual understanding of numbers. You just need to recognize patterns. Imagine a different set of cards with 13 military ranks from 4 different countries. That set of cards would work just as well.
At age 3 or 5 or thereabouts, you reorganize your understanding of those patterns into numbers. (Learning to count 1 2 3 ... is a different and simpler form, so don't confuse the two.) These numbers of disassociated from the quality of the object. You realize that the number 8 exists outside of the fact that it's counting 8 [of] spades. IOW, the way you organize quantities/ranks/orders has been abstracted. 8 houses and 8 spades have the number 8 in common even if houses and spades have nothing in common.
At age 5 or 8 or thereabouts, you understand that these numbers follow rules. That 2+2 is the same as 1+3 which is the same as 3+1.
How do you recognize a teacher? You take advantage of the fact that each transformation builds on the previous one. There's no skipping levels. We had that discussion in the Wheaton thread with some obstinately refusing to grok that idea. Anyway .. this supposes that in order to know addition, you have to known numbers and to know numbers you have to know patterns. You can't skip directly from recognizing patterns to addition (because you have no concept of what you're adding .. like what's the result of adding a village and a bunch of spades?).
Maybe metaphorically think of each transformation as adding another dimension. If you've ever read Flatland the metaphor should be obvious. Due to inherent limits of one's present level, it's not naturally easy to see the next level; whereas at the next level, nothing could be more natural than seeing the next level AS WELL as the previous level.
For example, if you're a 2D creature, it will be almost incomprehensible to grok what a 3D structure looks like. (Go ahead and try to picture for a 4D box looks like.) Whereas, if you're a 3D creature, you can easily comprehend what a 3D box is and how a 2D rectangle is a simpler aspect of the 3D box.
Kegan's In Over Our Heads (recommended) differentiate between what we are (subject) and what we have (object). We're not capable of stepping outside ourselves when it comes to seeing [a particular aspect of] what we are. All we can see is what we have. What we have for a given level is all the stuff from lower/past levels. What we are is the present level and we won't see it as something we have until we get to the next level.
Read
https://medium.com/@NataliMorad/how-to- ... 3f4311b553 (it's a shorter overview of the book)
Thus if someone is organizing concepts in a way you don't understand, you're below that Buddha (for the given issue, whether it's personal development). Of course it might be that they're talking about simple stuff and you just don't know the details yet. That's not what I'm talking about. I'm not interested in WHAT people are talking about but HOW they're talking about it. Suppose you (student and teacher) both know that WHATs. The distinction would be in HOW you are talking about it. Once you can both talk about something in the same way, you're at the same level. You would supersede the teacher (kill the Buddha) once you can talk about something not only like the Buddha does but in a way that additionally explains the Buddha.
IOW, to kill the Buddha you need not only be able to explain why you think the Buddha is wrong but also be able to understand why the Buddha arrives at their wrong conclusion. E.g. (the Buddha is only seeing the world as 2D intersections and that's why 3D creatures appear to pop in and out...). If you can't do this, you're either at the same or a lower level than the Buddha.