Life is a quest for health, happiness and the ability to marshal power to secure them both. That ability can be thought of, abstractly, as a bubble that surrounds us. The extent of the bubble reflects the extent of our capability to manifest our will in the world around us.
The arc of life is an attempt to expand that bubble to maximum dimensionality and extent, usually by joining our bubble with those of our colleagues in life's journey, and then to gracefully surrender control (separate) so that those that follow us can carry on in our absence.
The dimensions of our bubble include our physical and mental faculties, virtues and vices of character, the diversity of our relationships, and the skills we employ to defend our personal and material assets in a world that is often callously competitive.
Obviously, the geometry of our bubble is exceptionally complex, and for that reason, the interaction of our bubble with other bubbles is subtle and surprising.