Yes I see where you are going Godfrey and I definitely want to read further into this.
At the moment I am thinking that the issue may be that in glass half full / half empty issue. In the face of an ambiguous construction (the end of pain) we project onto that ambiguity what we think we "should" project there given our cultural overlay.
Today we are taught either a sort of oppressive religious absolutism or a sort of nihilistic nothingness or other assorted oppressiveness as a default position that would occur when our personal needs and desires are reduced to zero, and so when I hear "absence of pain" I hear nothingness and immobility and nothing attractive whatsoever.
However if your starting presumption is that being alive in the absence of pain entails a fully effective organism that is able to accomplish everything it has the power to accomplish (and not just does nothing simply because it doesn't want to do anything) then maybe the picture you get of "absence of pain" immediately transforms into such a powerful image - and maybe that is Epicurus' frame of reference.
But to me it would all boil down to that initial set of presumptions and references that - like all the atoms in the universe - we too are in motion and doing things smoothly in a way that we find makes for pleasure and happiness, and that initial set of presumptions and references cannot be left to ambiguity.
I strongly doubt that Epicurus left it ambiguous in his own time - I feel sure his other writings explained this much more clearly than the letter to Menoeceus - and I feel certain that given our cultural mess today that it is essential that this not be left ambiguous.
So yes we can say absence of pain constitutes an interesting generalized way to express the best state of existence, but the "then what is the person doing after that?" cannot be left to abstract notions that sound like "nothing," The explanation demands that the context and premises of the generalization be explained with clarity.
