BRIEFCASES ARE SERIOUS. Always have been. It's hard to imagine the daily nuclear launch codes, which traditionally have accompanied the POTUS in a briefcase, being shoved into a messenger bag. The idea of Don Draper carrying a gym bag into Sterling Cooper & Partners is downright incongruous. Even the noise a briefcase makes is serious business; that distinctive "tchunk" (halfway between a click and a "thunk") of the latches springing open conjures memories of a father, home from the office, extracting vital professional documents.

But...