Three guys came together and said, "'Who can be together in their very not being together, do things for one another by not doing things for one another? Who can climb up upon the Heavens, roaming on the mists, twisting and turning round and round without limit, living their lives in mutual forgetfulness, never coming to an end?' The three looked at each other and burst out laughing, feeling complete concord, and thus did they become friends." (6:45; Ziporyn)
There is something in this story and the one preceding that I find especially appealing, just as that great rarity, true friendship, is so appealing. This is only the introduction to a passage full of further implications, but a great deal can be mined right here.
Once again, laughter seems to be a clear sign of at least an inkling of transcendent experience. It need not be — there are many reasons for and kinds of laughter — but it most certainly can be. One can laugh alone, laugh at oneself or the world, but here it is shared laughter, sparked by a look, and this makes it all the more poignant. Shared beauty is beauty exponentially magnified. Yet, their shared joy is predicated on their mutual forgetfulness; very paradoxical indeed.
Our access to the meaning of this forgetfulness is perhaps easiest by way of the concept of wuwei (non-action), yet that is no less difficult to grasp. They are together by not being together. They help each other by not helping each other. Yet they are both together and helpful. They are together in such a way as to be non-dependent on each other, and this is what enables them to be truly helpful to each other.
Consider a relationship in which mutual dependence is the norm. We speak of the co-dependency of those in overtly dysfunctional relationships, but there is a sense in which most if not all of our relationships are thus. Self requires other, and 'other' is typically a kind of negation. My self is bolstered in diminishing yours. Or taken more positively, in thinking that I 'help' you, my self feels itself more affirmed. In either case, there is co-dependency. Mutual forgetfulness is a kind of non-dependency where mutual affirmation is decoupled from the ordinary self/other dynamic. Might we call it true friendship or true love?
"Roaming on the mists" is yet another metaphor for obtaining the view from Dao, and it is this which enables these three to be true friends. We "forget" each other when we fully affirm each other in the "clear oneness of Heaven". In this view, all things are equalized, differences and failings do not prejudice. "Looked at from the point of view of their sameness, all things are one."
Zhuangzi, and philosophical Daoism generally, often call for this kind of forgetfulness of others, yet this is understood as precisely that which enables the greatest possible love and benefit for each other that we can realize.
You can check out Scott's writings on Zhuangzi here.