It's taken me only three months of Porte Saint Monty to establish a reasonably predictable cycle of iterations through a few themes. I offer the Willa Cather quote as both defense of this pattern and prediction that it will continue.
Cather calls the collection of essays from which the quote is pulled Not Under Forty to indicate that the themes she discusses will not appeal to people under the age of 40. Cather regards the generation after hers as fundamentally different, possessed of new biases and values. She writes that “the world broke in two in 1922 or thereabouts,” with a tone of resignation very similar to how I regard, oh, 2007 or thereabouts. Change was no longer a continuation; it was a schism of worldview.
Possibly, regarding with queasy horror the generation under one’s own, is a universal manifestation of the human condition, triggered automatically by all who live to reach a certain age. Alternatively, Cather is simply saying that it’s difficult to say at 20 what the ghosts that haunt you at 40 are going to look like. Obsessions take time to form.