“The metaphorical style of presentation in Zarathustra only hints at its biological contents. In his notebooks from the period of Zarathustra, Nietzsche was more forthright. He wrote that the 'goal' was the ‘evolution of the entire body and not just the brain’. Overt references to the specifics of the physical evolution of man would have been ill-suited to the pathos of Zarathustra's speeches. Ought Zarathustra to have said something about, for instance, the quantity of hair, musculature, arm length, or head size of the Übermensch? This would have been unintentionally comical. In matters concerning the physical appearance of the Übermensch, Zarathustra confined himself to this advice for those contemplating marriage: ‘Do not reproduce yourself, but rather produce upward! May the garden of marriage help you do this.’" (page 261)
"Zarathustra uses graphic imagery to convey the idea in the speech 'On the Three Metamorphoses'. The initial stage of this process takes the form of a 'camel,' burdened with a plethora of "Thou shalts". The camel turned into a 'lion,' who fights the whole world of "Thou shalts" once he has discovered his 'I want,' but, because he fights, he is bound to the 'Thou shalt' in the negative sense. His ability to exist is consumed in an urgent need to rebel. There is too much spite and tension in this 'I want,' and the true leisure of creative volition is still lacking. A sense of self and fullness of life have yet to be achieved. These attributes are possible only when one becomes a child again and regains one's initial childlike spontaneity toward life on a new level: 'The child is innocence and forgetting, a new beginning, a game, a wheel that moves on its own, a first movement, a holy pronouncement of 'yes'.”(page 277)
The self-absorbed isolation and sensitivity would become much more pronounced in the final sane years of Nietzsche's life.