In her memoir She Matters: A Life in Friendships, Susanna Sonnenberg reflects upon significant female friendships in her life.

What prompted you to write the book?

In my mid-30s a very close friend dumped me. She had specific reasons why I was a bad friend, and I was terribly confused (and devastated) that she saw me that way. This got me thinking about how a friendship can serve a vastly different purpose for each of the two friends. I started to wonder about purpose—the gain and lesson—of all the friendships with women in my life. I set out to tell several stories of friendships, and with each story to write about a particular moment of life. I concentrated on women because women make things intense. We can’t help it.

Was the writing process different this time than for your previous memoir, Her Last Death?

With Her Last Death, reviewing childhood was painful, and this time everything felt calmer. I trusted my instincts more, had less stress about publishing, but I don’t think I’d call it easier. What you learn from writing one book is how to write that one book. Then you start again.

A concern for anyone writing a memoir is how much to expose of those who are close and dear to them. How did you handle this issue?

It was often in my mind. One woman had an affair that had dramatic consequences for our friendship. After time and work she and I are close again, and I asked if she was okay with me writing about it. She said she was. For other friendships, certain elements of identity and context are disguised so that I could write about important events we shared. But all of this came in later drafts. You’ll never write what you have to write if you take every agenda into account.

Has completing this book shed new light on any aspect of yourself?

I thought I had three or four really significant friendships, so I was startled to see how many people had mattered so deeply, how essential they were to who I was. Who I am. I thought I didn’t have continuity in my life, and I was envious. But I saw another kind of continuity I had not defined before, strands of relationships running through my life, sometimes a focal point, sometimes not. We make what we can make.

What are you working on next?

Let’s not tell my kids I’ve started another book. Not yet.