You never realize human life and the physical form of the 'human' until you study it. Each person has the exact same bones, parietal, sphenoid, ethmoid, maxilla etc.; yet we all look so insanely dissimilar. The basis of life begins at the bones, and they continue to grow and regrow after careless humans break and fracture the mainframe of their existence. After studying human anatomy it is difficult to just call a face a face or an arm an arm. They are so much more complex than that.