The human brain is a funny thing. When it has been so programmed to look for darkness that it simply filters out light, light becomes an ineffective tool to expose the darkness.

Instead, you need to swamp it with darkness. You need to push so much darkness that it becomes overwhelmed.

Consider you are looking at a picture of nothing but noise, and you've trained your brain to look for patterns of green in that noise. You begin to filter everything that isn't green, until you can see all the subtle patterns of green. Shoving something red in front of you won't matter. But, if you make the entire screen green, if green becomes so ubiquitous that there simply is nothing else, then you can no longer see patterns of green. There's too much of it. In that case, your brain finally flips and realizes it is easier to search for "anti-green" It's only at that point you can introduce red in a meaningful way.

This is a bad metaphor for the precipice, or alternatively how you can only break bad habits when you have reached rock bottom. We need to push to the point that any more green just overwhelms them with too much signal, and they begin seeing the noise again. Because what they've been filtering as noise is actually the truth.