Advancements in healthcare, exercise, diet, and quality of living have transformed retirement from the end of one's life into the beginning of an exciting new chapter. But living longer isn't the same as living well. An increased lifespan is going to create some important challenges that retirees need to prepare for as early as possible. To maximize your Return on Life in your 70s, 80s, and beyond, start making purposeful investments in these three areas.