> That doesn't help me understand 3D space. It helps me understand 2D changing over time. If you treat time as a dimension then you now understand 3D. There i

> That doesn't help me understand 3D space. It helps me understand 2D changing over time. If you treat time as a dimension then you now understand 3D. There is a book called Flatland that takes place in a 2D world occupied by 2D shapes. The shapes can only perceive two dimensions. One shape encounters a sphere, but to the shape, the sphere looks like a changing circle. It makes you realize that it's probably impossible to conceptualize a sphere if your only frame of reference is two dimensions. Similarly, in your maze example, you're placing one piece of paper over another one, meaning the paper already exists in 3 spatial dimensions. How can I place one 4D object "over" another one?