"There is a fish in the Northern Oblivion named Kun, and this Kun is quite huge, spanning who knows how many thousands of miles. He transforms into a bird named Peng . . ." (Zhuangzi 1:1; Ziporyn) Peng is similarly huge and he rises tens of thousands of miles into the air in order to make the journey to the Southern Oblivion. Thus do we have a metaphor for the flight of existence, a journey from Oblivion to Oblivion.
Many commentators point to the evocative character and intention of the Inner Chapters of the Zhuangzi; they are not intended to assert and teach doctrines or principles, but rather to shake us out of our own that we might discover a new freedom which will enable us to make our own journey well. Thus, though we must do our best to understand what Zhuangzi intended to say, we fail of his intention if we do not rise out of it to take flight into our own unique interpretive journey. And thus, these responses to Zhuangzi, though attempting to remain true to his meaning, do not claim that they always do nor that they always should.
Daoism looks at the human experience as only complete when seen in the context of its beginning in Mystery and end in the same. Life is best lived when aware of its rootedness in Mystery. As in Zen, we are invited to become what we 'were' before our parents were born. And what is that? We do not know. But it seems safe to assume that if we 'were' at all, it was not as that which possesses identity. Words which attempt to describe this are "emptiness", "nothingness", the "void". This awareness informs our present being in the world. It does not negate existence, but it does put it in context. And since the human predicament is such that we are ever aware of the tenuous nature of our existence, this context is not optional.
If the Northern Oblivion is birth, the end of the journey in the Southern Oblivion is death. Daoism similarly would have us allow death to inform life in how best to live. Death may be the Ultimate Teacher refered to in the title to Chapter Six. In the context of our being bracketed from beginning to end by Oblivion, and in view of the undeniable impact of this realization upon our awareness, however sublimated, how can we not allow it to teach us? Conventional wisdom sees it as a negative and thus an impetus to 'make the most of life'. Though Zhuangzi would not necessarily disagree, he would suggest that death is not a negative, but a positive. "That which makes my life good also makes my death good." We are invited to affirm the entire package, from Oblivion to Oblivion.
This affirmation can be more than simply mental assent; it can transform our being-in-the-world. Thus, Zhuangzi ends this passage by concluding that “the sage has no fixed identity”. He has in this sense returned to the emptiness that he ‘was’ before his parents were born.
You can check out Scott's writings on Zhuangzi here.