To forget your self is to be actualized by the many things.
A skier mustering whole body-and-mind, totally absorbed in the activity of skiing down a mountain, forgets his or her “self” and is actualized by the myriad dharmas (the many things). With no ideas of self and not self, there is simply swoosh, swoosh, chunk, swoosh, swoosh. There is no “snow” there is whiteness, coldness. There are no “sounds” there is shoo, shoo, tweet, weeee! There is no “thinking” there is left, right, straight, watch out. In Shobogenzo, Hossho, Dogen gives us a delightful expression of this experience:
In the Dharma-nature there is no “non-Buddhist” or “demon,” but only “Come for breakfast! Come for lunch! And come for tea!” (Gudo Nishijima & Mike Cross)
The Genjokoan continues:
To be actualized by the many things is to allow the body-and-mind of your self and the body-and-mind of other than your self to fall away.
…When the body-and-mind of “your self” and the body-and-mind of “other than your self” both fall away, there is only, “Come for breakfast! Come for lunch! And come for tea!” This is why people often laugh upon their initial enlightenment experience; all along your inherent awareness, that is, your buddha-nature or true-nature, has been functioning perfectly…
One Buddhist scripture, the Surangama Sutra, contains a passage that presents this point so directly that it is included as case ninety-four of the Blue Cliff Record:
The Surangama scripture says, “When I do not see, why do you not see my not seeing? If you see my not seeing, naturally that is not the characteristic of not seeing. If you do not see my not seeing, it is naturally not a thing–how could it not be you?”
–The Blue Cliff Record