The notion of a trajectory involves some patterned movement of a single object across space and time, and evokes images of inanimate objects, propelled by powerful forces, streaking across the night sky in a dramatic and predictable arc. In the sociology of the life course, we are more concerned with animate human actors whose trajectories are more subtle and who are more readily “bumped” off-course; but we nevertheless typically maintain that they are indeed propelled by powerful social forces that constrain, even if they do not completely determine, the shape of their lives. It is precisely because continuing in the same direction in which one is already headed is so much expected, in fact, that we find the exceptions interesting. We are fascinated, as social scientists and as fellow travelers from cradle to grave, when people appear to dramatically shift course, get “derailed” or “jump off the track,” reinvent themselves and their daily lives, and reshape their future prospects. In comparison, we tend to be less interested in that which makes these exceptions remarkable – the strong persistence over time, for most people, of their current circumstances. Thus, dramatic turning points are foregrounded while trajectories are backgrounded. In the social stress literature, a similar emphasis can be seen in the preoccupation with life events to the relative neglect of chronic, persistent social conditions.