Our minds are accustomed to three dimensions and object permanence

Mind palaces are a great example of how natural spatial reasoning is for most brains. We can easily memorize the act of mentally walking through a space. There is a natural, intuitive spatial sense humans have that spatial interfaces have the opportunity to take advantage of. These types of interfaces should be even more natural than

99% accurate occlusion will be the final step to this feeling like magic

we will be able to leave instances of apps open in rooms that we leave