In Genjo Koan, Dogen continues his discussion with the following lines (paraphrased below):

To study the way is to study the self.
To study the self is to forget the self.
To forget the self is to be experienced by potential.
To be experienced by potential is to let your body and mind, and the body and mind of the external world, fall away. 

There is a state in which all traces of realization are forgotten, and a state where the traces of forgotten realization are manifest for a long, long time.