A Boat Against the Current.

My memory is nowhere near as good as I would like it to be. Although I have no trouble recalling the worst and/or most embarrassing incidents in my life, and I could recall enough of what I read to do okay in school, my memory has never been prodigious enough to make me serious money (e.g., on quiz shows such as Jeopardy or Who Wants to Be a Millionaire?).

Several years ago, in writing chapters of a memoir, I sometimes wished I could recall more. That was a big reason why I attended a book-signing event for actress Marilu Henner at Bookends, an independent bookstore in Ridgewood, N.J., in the same county where I live.

I don’t lose my mind over celebrities. Even those associated with a show or film I’ve enjoyed, such as Ms. Henner’s classic sitcom Taxi, don’t necessarily interest me.

But a celebrity writing or talking about memory—yes, that does interest me.

Ms. Henner was promoting her new book, Total Memory Makeover. She spoke without notes, laughing easily and often, constantly engaging the audience. She even conducts classes on memory, and based on this appearance, I doubt if she has any problems holding attendees’ attention.

I hadn’t kept up with her career much after she left Taxi. After her appearance, I learned from the Internet that she’d appeared on Broadway in Chicago and The Tale of the Allergist’s Wife—and, as the grandnephew of a Titanic survivor, I found it intriguing that she had played, in a 1997 TV movie, one of the most famous survivors, Margaret Tobin “Unsinkable Molly” Brown of that disaster. I wish I had learned more about her background before the event.

Nearly all of her eight prior books deal with health. Even the title of her inevitable showbiz memoir, By All Means, Keep on Moving, sounds like an exhortation to exercise—and, indeed, she did discuss in it her strong belief in healthy living, in between accounts of her career and relationships to date.

Though it has a whole chapter dealing with the physical aspects of memory, this newest book is primarily concerned with memory as an aspect of mental health.

Ms. Henner disagrees with those who think that “forgetting” per se might be a necessary element of forgiveness. On the contrary, she urges readers to relieve bad memories in an effort to prevent recurrences of events or behavior patterns (e.g., unhealthy eating, bad relations) holding us back in the present.

I’ve perused a couple of other books on the subject of memory before—notably, Joan Minninger’s Total Recall and the long-ago Harry Lorayne-Jerry Lucas bestseller, The Memory Book—but Ms. Henner’s is different in its focus on the autobiographical element.

That’s not surprising, since the actress is, as documented in a 60 Minutes segment from a couple of years ago, one of only a dozen people who have Highly Superior Autobiographical Memory (HSAM), the ability to recall even the smallest, most trivial detail on virtually any day of her life.

She can even hear a specific date and know what day of the week on which it occurred. This ability has led her recently to become a consultant to Poppy Montgomery’s CBS series, Unforgettable.

In the course of her talk, Ms. Henner noted that those with HSAM can remember not just what was going on in their own lives on a certain day, but what was happening around the world (July 16, 1999 was the day JFK Jr. died).