This is what Stroebe and Schut described as the dual-process model of grief, in which we “oscillate” between “loss oriented” and “restoration oriented” phases as we process our grief.

A Personal Perspective: As we grieve, sometimes we look backward, sometimes forward. This is the dual-process model of grief, and it's both hopeful and stressful.

Heard of the "five stages" of grief? Psychologists say the model is problematic and not supported by evidence.