Burton Watson, in his preface to Experimental Essays on Chuang-tzu (Victor Mair, ed.; 1983), makes several interesting observations, some of which I will share here.
When he was commissioned to translate four classics of Chinese philosophy, he purposely left the Zhuangzi until last, first because he hoped that this would better prepare him to render this more difficult work, and second, because it gave him something to look forward to. In the case of the latter, he points to the way in which the Zhuangzi presents "flights of language so rapturous that they threaten to go beyond the borders of meaning." And this, he implies, requires the translator to follow him 'out there', to somehow imagine what this experience entails. And that, in my opinion, was very much what Zhuangzi himself hoped to accomplish.
Another reason he gives for having looked forward to his work with the Zhuangzi is "the incomparable wit and humor that lie at the heart of the Chuang-tzu" which he describes as "the single most potent device employed by the writer to jar the reader out of his mundane complacencies and waken him to the possibility of another realm of experience." If we require "jarring", then humor seems a particularly humane way to go about delivering it. And it is also a skillful means very much in harmony with its end, namely to enable our carefree and playful wandering.
However, he goes on to say this same humor and playfulness renders the Zhuangzi especially difficult to understand. "If he parodies so many others, is it not possible that he parodies himself as well?" How do we know what to take seriously, and what not? Perhaps, none of it. Surely, if we have captured the meaning then we need no longer take any of it seriously. Isn't this the whole point?
Finally, on a more critical note, in grappling with what he sees as the central experience advocated by the Zhuangzi, namely the "realm of nondualistic thinking", Watson seems to fall into the trap of believing that the Zhuangzi cannot have been meant to stand alone, but must have had "some similar exercises [to Zen koans] or set of practices that were meant to accompany the book and assist the student." To my thinking, this is equivalent to saying the Mumonkan or Blue Cliff Record, two compendiums of Zen koans, should have come with books of "answers". The whole point, of course, is that there are no answers, only the possibility of experiencing a meta-awareness of the non-dual. The Inner Chapters of the Zhuangzi are themselves a koan.
You can check out Scott's writings on Zhuangzi here.