The basis of this idea comes from the law: "as above so below"... that creation reveals itself in and through the infinite stages that express its existence; stages that we see, for instance, in the idea that a human embryo goes through the entire gamut of nature before "arriving" at the human form. These stages are single cell, amphibian, mammal, and human body... because all of these levels (of nature) reside within us. Now, take this idea and apply it to one's developing understanding.

You see the truth in some moment, through some event, etc., and (at first) there's nothing bigger; the insight floods all of you, and it seems you know the whole story. But the next week, or month, you're in a similar situation and "bang"... suddenly you see that what you saw the first time was just the beginning of something grand; you also see that now you know you didn't know the "big" picture, but only thought you did. And this happens over and over again for anyone who is working on himself/herself.

So this new wisdom (you keep realizing) is like a box that holds seven boxes (the number having to do with an esoteric idea about the seven levels of being, etc.) Each "box" of new discovery about yourself is really a smaller box within a greater one, just waiting to be opened. With this model, each new understanding you've gained isn't lost, but only becomes a part of a bigger, more eternal wisdom... all waiting within that "box" called "you."