It refers to the dark side of the person and their inability change and is a perfect metaphor for the status quo. One could think about moving to a specific latitude at a specific month and time to get the shadow perfectly beneath the person so they can jump on their own shadow. But change probably comes from a different metaphor all together. Problem as a body with physical reactions. The past is viewed as war with casualties to be put at rest.
Mediator returns to the journey and locates the past.
In general, past and down metaphors are bad and future and up metaphors are good. This is also a 'time is money' metaphor. Return to the journey. The goal, as a destination, is added to suggest the total journey. This is a weight metaphor.