You could imagine a conversation in your head between two people, on just about anything.
You know what they will say because you imagine the words for them to say.
If you let go a little, and let your imagination move a little more freely, the perspective shifts a little, and their words are a little freer, a little less expected.
If you let your imagination go completely, they might speak all themselves, almost as in a dream, the words playing out without your expectation.
So that when hallucination plays out, its from the perspective of unknowing, rather than knowing.