One lesson from the school of experience is that major life transitions are easy to imagine and hard to navigate. Even with meticulous planning, transitions usually involve dealing with occasional setbacks and unexpected challenges. Successful transitions require flexibility, a willingness to experiment, and the ability to recalibrate expectations.

A recent report by the demographic consulting firm Age Wave and the financial-services company Edward Jones examines one of life's biggest transitions: retirement. "Resilient Choices: Trade-Offs, Adjustments, and Course Corrections to Thrive in Retirement" focuses on the challenges and adjustments pre-retirees and retirees confront. The authors use the four pillars of retirement — health, family, purpose, and finances — to show how important course corrections are in creating a successful retirement.

Retirement rarely goes smoothly. A majority of retirees surveyed in the report — 69% of men and 81% of women — experienced at least one "curveball" or "cannonball" event. The top three are widowhood, divorce, and a significant financial setback. A majority of the retirees surveyed also experienced a "windfall" or good fortune, with becoming a grandparent, taking a dream vacation, and discovering a new or renewed purpose in life topping the list. The combination of setbacks and windfalls usually requires unexpected and practical course corrections across the four pillars (or at least one).

Finances matter. That goes without saying. So does your health and connections with family and friends. Yet finding purpose or multiple purposes seems to lie at the core of making a successful transition to retirement and a framework for navigating course corrections during retirement. "Purpose is powered by a desire to do something for others beyond yourself, to contribute to the greater good in a meaningful way," writes Joe Casey in Win the Retirement Game: How to Outsmart the 9 Forces Trying to Steal Your Joy.

The Age Wave/Edward Jones report describes the main activities where people typically find their purpose. Among them: volunteering; faith-based practices and spiritual explorations; hobbies; pursuing adventures; and work (which also brings in an income).

The primacy of the search for purpose while planning for retirement and during the retirement years reflects that the latter stage of life is less associated with leisure and rest these days. Retirement is increasingly seen as an opportunity to experiment with new choices and challenges. Finding purpose in the transition to retirement can make a big difference to an individual's quality of life (and also benefit the wider society).

Chris Farrell is senior economics contributor and a "Marketplace" commentator for Minnesota Public Radio.