What we experience is a controlled hallucination. Our brain creates our world, from various inputs based on what we have sensed before. Our brain creates our world, through trial and error. A tree only becomes a tree once I have the word, the smell, the feel and the knowledge of what it is. It is closer to the string of noise we hear when someone speaks a language we don't understand. Words aren't separate from each other, they become separate as we add meaning and context. We don't have to understand the world for a best guess to be useful. Tacit Knowledge is when I understand something, but don't know why I understand it. I may have a useful story to make sense of it. Whether that story is right or wrong doesn't matter, if it helps me do what I need to do. When our hallucinations clash, we need new stories. Shared stories.