The news that the Millrose Games are leaving Madison Square Garden after 97 years to relocate uptown to the 168th Street armory reminds us of how indifferent we are to track and field. And yet, in a coincidence of timing, we remember, too, that we were not always this way. Friday’s announcement came almost exactly 40 years after an event that placed the sport, however briefly, front and center in the consciousness of the American public.