I came across all kinds of fascinating studies in researching this book, but one of my favorites comes from Jack Zenger and Joseph Folkman, called “How Age and Gender Affect Self-Improvement” (Harvard Business Review, 2016). Drawing on Carol Dweck’s work on fixed versus growth mindsets, they studied seven thousand businesspeople through self assessments and 360-degree reviews from coworkers. They found that older people were more open to self-improvement and less defensive to criticism because they had evolved over time to focus on improving instead of just proving themselves. And the researchers found that the more self confidence individuals have, the more willing they are to change.

But we are usually not aware that when we look back in time, our penchant for pattern-making leads us to be selective about which memories have meaning. And we do not always make the right selections. We build our story - our model of the past - as best we can. We may seek out other people’s memories and examine our own limited records to come up with a better model. Even then, it is still only a model - not reality.

People often find potential more interesting than accomplishment because it’s more uncertain, the researchers argue. That uncertainty can lead people to think more deeply about the person they’re evaluating—and the more intensive processing that requires can lead to generating more and better reasons why the person is a good choice. So next time you’re selling yourself, don’t fixate only on what you achieved yesterday. Also emphasize the promise of what you could accomplish tomorrow.

Reading a CT scan alone in a room is abstract and distant. Reading a CT scan when a photograph of the patient is staring back at you makes it concrete and personal. In both traditional sales and non-sales selling, we do better when we move beyond solving a puzzle to serving a person.

But the value of making it personal has two sides. One is recognizing the person you’re trying to serve, as in remembering the individual human being behind the CT scan. The other is putting yourself personally behind whatever it is that you’re trying to sell.

We found scant evidence that the people in our study had an explicit goal of working until a target retirement age to be followed by a life dominated by leisure. The vast majority of people in this study remained engaged in some permutation of a hedgehog well past the age of 60, in some cases into their 70s, 80s, even 90s. That said, nearly half the people in our study had a “retirement” from one hedgehog partway through their lives and faced the challenge of transitioning to the next one. Sometimes these were relatively smooth transitions, such as Tenley Albright’s shift from skating to surgery.