Young children seem to have an early understanding of the world around them, and the people in it. Before children can reliably say "ball", "wall", or "Saul", they expect balls to not go through walls, and for Saul to go right for a ball (if there's no wall). There are different proposals out there for the cognitive computations that underlie this basic commonsense reasoning. I'll focus on one proposal in particular, and suggest that a "rough rendering and de-rendering" approach can explain early expectations about object solidity, cohesion, and permanence. From there I will expand the proposal to some more recent work on imagery and imagination, including non-commitment in imagery, and the importance of physical properties in visual pretense.