Accidental Overdose: Suffering and Resilience

We finally learned how my mother died last week. It was an accidental overdose of pain medication. I'm grateful to know it wasn't suicide, and yet still find it extremely sad that my mother's lifelong battle with emotional and physical pain caused her death. She never transcended a life of suffering in this incarnation, she never broke through to a life of real joy and healing. I hope to one day understand why I was born to her with tremendous resilience that seems to be a part of my inherent nature and she seemed to have so little resilience at all. Where does resilience come from: nurture or nature or both? Why are some people broken by one tragedy, and others can not only withstand many tragedies, but also turn them into opportunities to serve others who suffer? I just don't understand. Now I have an even deeper reason to want to know why we were so different and what, if anything, can be done for others who lack inherent resilience.