It’s as if men and women experience a hormonal convergence that opens up new realms of compatibility.Scientists also report subtle brain changes that make us more introspective and solitary and less irritated by small annoyances. Of course, the research on the brain and aging is still far from conclusive. Some of it suggests changes that might be less then welcome. Yet a certain degree of midlife mellowness, complemented by feistiness — and the gains of plain-old experience — allow many partners to find the all-important space they need. A private comfort zone gives each of us room to grow, room to strut, room to step back and revise our perspective.As each woman here discovered, change occurs from the inside out. Once they shifted their own priorities, their marriages began to evolve. Each woman, in the course of renegotiating terms of endearment with her husband, gained a new perspective on him, one that was more sympathetic than she would have predicted.Those marriages that endure are about the intimacy of shared history and the joys of embarking together on a journey of reinvention and self-discovery. When Lauren came back from Peru, she made three resolutions for herself: "Express yourself, live at your own pace, and experience gratitude." They work for me.Originally published in MORE magazine, February 2007.