[they pause, and consider how to explain this in a way that someone else could understand]

Imagine you're running your fingers over a wall. It's smooth to the eye, but if you're paying attention, your fingers feel the truth. There's subtle bumps, and indents. Faint cracks in the surface. Now take away the wall. Nothing to feel.

But the cracks are still there. That's what it feels like. Cracks on the surface of a reality that doesn't exist.