A traditional undergraduate entering college this fall was probably an infant on September 11, 2001. Across my courses, most of my younger students no longer remember the day itself. They remember fragmented impressions of its aftermath, as seen through the eyes of older family members and teachers. Or they remember only the impression that something really bad had happened. They summon up images of adults in tears, holding mysterious school assemblies or sending them home early, trying vainly to comfort themselves by offering comfort to uncomprehending kids.
September 11, which I do remember vividly, now occupies the same role for many of my students that the late days of the Cold War had for me. It was a moment of tectonic power, causing frequent aftershocks ever since, that defines their lives without their really being there for it. But there is a difference.