As Steve at brip blap recently pointed out, whether fairly or unfairly, we tend to make judgments about people based on what it is they do for a living. What we "do" is among the first questions asked between people meeting for the first time. And for many entering retirement, the loss of that identity is often the hardest change to get used to.
"For many people, what they "do" - their job - is not enough. We want to be defined by what we hope to achieve in this life. Determining what - if anything - we can achieve is the first step to understanding whether our job is a part of that achievement, or merely a sideshow."