Hardened by time.
Man born from clay, being formed into shape.
Born moist and easy to form.
Influenced by society, environment, and upbringing, they being the hands shaping the curves and bends.
As time goes, the clay thickens, the form dries, the walls wrinkle, the uncanny bends do not bend no more, all the curves, all the faults, all the clay is now set into stone.
Unchanging, waiting until the end of its time where it cracks then inevitability turns into rubble.