When the psalmist praised God, proclaiming himself "fearfully and wonderfully made" (Psalm 139), he alluded to the mysteries of our beingness that mystics through the ages had discovered
--- that the reality of who and what we are is complex. Indeed every human being is a microcosm of the macrocosmic Universe, both physical and nonphysical.
How complex is a person's state of beingness? If a person had no idea of the inner physiology of the human body and suddenly viewed it for the first time, most assuredly there would be a sense of amazement. Consider then that there are still other levels to a person's state of beingness that are just as complex, if not far more so.
Every day of human life most people go about their lives not thinking about the physiological workings of their bodies
--- simply accepting that their outer reflections in their mirrors reflect who they are. Only when people are not feeling well are they reminded that they are more than the outer image of themselves. So barring illness, most people go about their lives without an awareness of the intricacies taking place in the inner workings of their bodies.