Many social commentators, probably rightly, assert that Western culture is in the post-phase: Post-modern, post-religion, post-civility, post-bipartisan, post-patriotic, post-prudence, post-hope, post-tolerance and, perhaps, most inarguably, post-truth. But the “post” that is the topic of this month’s installment of “Bubble 3.0” is based on the thesis that the relatively recent phenomenon of a comfortable retirement is now also increasingly a thing of the past.