Wikipedia has this post about the album.
There’s a lyric here — “I know you know I know you know that I know that you know…” * — that illustrates the idea that human minds are able to speculate on what other minds are thinking, to three or four orders (though not children; it takes a while for children to develop this ‘theory of mind’). It reminds me of the Ted Talk we were listening to this morning as we drove to the trail head of today’s hike. It’s a fascinating talk about the subjunctive, a grammatical ‘mood’ that exists in English and not in some other languages, like Vietnamese, and therefore an example of how different languages really do allow, or inhibit, different kinds of thinking. (And the subjunctive is, perhaps, the philosophical essence of science fiction.)
*Reminds me a bit of that punctuation challenge, to make sense of “John, where Sarah had had had had had had had had had had had the teacher’s approval.” Insert the right punctuation marks, and it makes sense.