Falling into Place discussion

This book is one of my favorite books. It was such a unique twist on the usual suspense stories I read. I really liked the incorporation of physics equations and rules to get the point across. The time jumps also made so much sense that although varied they flowed. This book was raw and emotional and truly expressed Liz and her emotions in a way that as a reader I felt the same way. My biggest question that I can't seem to find the answer to is who is the narrator. Personally I always imagined it as the young and happy Liz since the narrator talks about blaming them self and disappearing after her father's death, but I want to know what others thought.