When dream predators read in the language wall, explore it, expose its joints and additions, they come across gaps in meaning. They are interested in the places where the language wall decays. They track down the weathered rudiments that have fallen out of it. They know that these are only noted by dreamers and poets.
When the bricks of the language dissolve, crumble, when their contours are washed around, when they lie idle, they can unfold their invaluable value in dreams as keystones.