Active Forgetfulness and Eternal Recurrence

While Nietzsche only briefly alludes to "active forgetfulness" in the Genealogy of Morals, he significantly illustrates it in the 'Of the Vision and the Riddle' chapter of Thus Spoke Zarathustra--the image of the shepherd biting off the head of the snake that is choking him.  But, the latter symbolizes the liberating effect of the affirmation of Eternal Recurrence.  Thus, Active Forgetfulness and the incorporation of the past are two facets of one and the same Janus-faced "moment" produced by that act of affirmation, which is why he asserts, in GM II, 1, that there is "no present" without Active Forgetfulness.  In other words, the interpretations that the doctrine of Eternal Recurrence is an expression of Nietzsche's nostalgia for some bygone era neglect the relevance to the doctrine of Active Forgetfulness.