At this hinge of life, between a 9-to-5 career and the other side, between the frame and the door, if you like, we open the door and walk through. Sometimes — most times — that means saying goodbye to people and places we have loved. The flip side of loss is new experience. Dwell on the one half and you have always lost; live in the other, and there is the excitement of new sheets in a strange bed, a grail and ewer on the night stand, unplowed fields in the window, the latch on the broad-swinging gate. Different animals, new terrain.