Everything man has placed on the moon or Mars could fit into a 1300 square foot apartment.
I think this bears some similarity to big city folk who really never live in the woods freaking out about nature, somehow assuming that forests are tiny little nothings that they saw once at a rest-stop without realizing that the trees go on continuously for hundreds and hundreds of miles (with some two lane roads to cross). Having grown up in a place with endless trees, I have gone days without finding evidence that humans had ever been on this planet, and I live in the Eastern US. We have 10 states with a rural population density of 5 persons per square mile or less, and almost all of those densely packed people live in rural towns.
If you quit spending all your time at Starbucks and the Galleria and go into the wastelands
, you'd see that the vast majority of the US is like Mars, or Mars with scrub, grass, or trees.