Everything else is learnt. Newtonian physics. Sharp vs blunt. Light vs dark. The very same object can look different in different lighting, and from different angles. One object can occulde another. Objects can be interacted with. There are self-directed things. Etc. The best we can do is apply our learnt knowledge/sense to new situations, with possibly some experimentation on the way.
My take on the definition of Intuitive Design: The maximum intuitive design requires the minumum cognitive abstractions to parallel an existing model and mininimum experimentation, resulting in an understanding which contains the maximum truth with maximum confidence, delivered to the the maximum diversity of people