I studied Kubler-Ross’s anecdotal study on the stages of grief in college back in the 70’s.  It was fresh theory on the then rarely explored topic of dying. Modern hospice was a new concept and medical professionals welcomed her insight.  To my knowledge, her research was based on the observation of the patient. I don’t know how much scientific study went into those left to grieve after a death. I’ve never been completely comfortable with the way her model has been interpreted, especially as assigned to bereavement. I don’t think her stages are linear (later in life she confirmed that same observation) or prescriptive. 
Now regarding her quote-I honestly don’t remember ever reading it until now, but find it her finest declaration. It’s the “whole again” with which I personally wrestle. Yesterday, I shared that I still felt like half of a union because I cannot figure out how to loosen the spiritual glue of “two becoming one.” Will I need that freedom to regain wholeness or am I truly richer with the imprint of this sacred past?  
At least, I’m naming my quandary.