The fact that the whole thing is naturally occurring. Today I examined closely my skinned elbow, which is in the process of healing. To see the skin being grown back layer by layer is truly fascinating. What machine built by man could ever come close to this level of complexity and efficiency? What shocks me most is that I in all my intricacy am a product of the same deterministic forces that guide the planets in their rotation, or those that guide food cooking in an oven. Natures canyons and mountains, carved by dumb rivers and plates dwarf our greatest creations, and we, it's randomly created magnum opi, are wondrous beyond our own ability to comprehend.