Very well described, as longevity without quality of life is pointless. That's my current challenge. How do we live a productive, active and engaged life up to the very end? I've seen too many people including family members go through things that they never anticipated or planned for, but the physicians involved suggested all sorts of treatments to keep them alive. Simply staying alive for a long time misses the point. Living a long high-quality existence where one is vital, engaged, and active up to the end is the goal. Ideally, the graph of life quality should remain steady in very slow, controlled decline for most of the later duration of lifespan and then drop like a cliff at the very end. Strict ketogenesis and exercise are my ways of supporting this as well.