just a handful of people. Frankly, it may be zero

From a handful to zero skips what? One aka each one being.

No need to know, you know?

Need (all perceivable) towards know (ones perception)...tempted by want (one another's suggestions).

how in the dark these people are kept

One cannot be kept in darkness...ones free will of choice keeping suggested information within mind/memory; casts darkness (ignorance) over light (discernment).

Light moves through one as perceivable inspiration and cannot be kept.

the highest levels

Level implies balance aka the moving foundation for adaptive choice rising within. Choosing to reach higher levels draws one away from foundation into imbalance.