How can suffering be a natural part of well-being?

UCLA's Susan Smalley writes eloquently about "Why Well-Being Is Not the Absence of Suffering". A few excerpts:

Well-being is not the absence of illness, disease, or pain and suffering -- that is, life's difficulties. Rather, it is an acceptance of such challenges as part of the human condition, not unique to any one of us. And in the acceptance of this truth, there is a choice to be made: how will you relate to life's challenges?

Whether we know it or not, we choose all the time among a multitude of options. If we bring these choices into consciousness, we discover the vast range of freedom afforded. When you choose to accept suffering instead of wanting to change it, a sense of well-being arises, regardless of external circumstances. The great thing is, we have the freedom to make that choice. In some cases our range of external possibilities is limited (in cases like terminal illness, life itself may not be an option), but we always have a choice in how we relate to pain and suffering.

Once, I met a doctor who came from a war-torn country in Africa and was now living life as a cab driver. He told me he had felt discouraged, regretful, and frustrated by his lot in life until the day he consciously chose to accept his life as a cabbie and began to learn from it, with an open curiosity that changed his level of happiness forever. No longer angry and frustrated, he became curious and talkative to his passengers, who opened their hearts to this caring man and expressed their own dissatisfaction with life. They never wanted to leave his cab because in that car was a man who was content with life.