Every once in a while, someone you thought you knew does something that makes you realize you didn't know them at all.

Case in point: The centerpiece of Reeve Lindbergh's collection of essays, "Forward From Here: Leaving Middle Age and Other Unexpected Adventures," centers on the discovery that her father, aviator Charles Lindbergh, had three -- three! -- alternate families spread through Europe that he managed to keep secret from his official wife and children in the United States.

This discovery landed like an anvil 30 years after her father died of cancer, and two years after her mother died of Alzheimer's. It turned out that Lindbergh had fathered two girls and five sons out of wedlock when he was 55 to 65 years old.

This from a stern, moralistic disciplinarian who once wrote a letter to Reeve's sister when she was at college, castigating her for potential promiscuity. The European families didn't know that their father was Charles Lindbergh -- with them, he used pseudonyms.

And here we all thought his terrible judgment was limited to an unfortunate enthusiasm for National Socialism.

Life continually seems to offer opportunities to be disappointed in one's parents, but Lindbergh apparently wanted to be sure to leave enough disappointment behind for several generations, in a half-dozen countries.

"Of all the people I have known and loved, my father is the one I found most impenetrable," Reeve Lindbergh writes, and that certainly seems a fair comment.

What makes the situation completely impassable from her point of view is that there is no way to resolve it. Lindbergh himself is gone and unable to offer any enlightenment as to what he thought he was doing, other than satisfying his latent urge to be fruitful and multiply. Likewise, her mother, who, a friend tells Reeve, "knew but didn't know," isn't around to help.

So Reeve circles, learns to live with the ridiculousness and forms some rough but not untender bonds with her newly discovered family members.

The essay, unlike most of the pieces in this collection, ricochets between an authentic anger and a wry bemusement. She makes a pilgrimage to Europe to meet her newly discovered half-brothers and half-sisters. "Every so often, the oddness of it all came through. Once, during a meal, a European half-brother and I looked at each other and slowly shook our heads, wordless. This is absolutely normal, and completely insane, too."

Reeve Lindbergh is an accomplished writer -- I fondly remember "No More Words," her memoir about her mother, Anne Morrow Lindbergh -- but she is perhaps too completely a part of her generation.

Her style is ruminative, gently feminist, slightly predictable, softer than Ellen Goodman, but not radically different in terms of subjects -- the aging of baby boomers, life in the country, the seasons, all the way down to the deeply uninteresting and trivial. There is way too much about Brussels sprouts, for instance.

But the getting of wisdom is not always deep; sometimes, truth comes disguised as good advice. Reeve tells what she learned from the late editor Helen Wolff, which comes down to two maxims: Writers should shut up and write, and once it's cleanly written, leave it alone; don't keep fussing "like a housewife plumping pillows." She also offers a cure for mild depression: exercise, socialization, routine and nutrition.

Reeve is, in other words, a lot like her mother, and that's meant as a compliment.

When Lindbergh grapples with something with weight -- a retreat to Captiva Island, 50 years after her mother went and came back with "A Gift From the Sea"; her father's stupefying layers of emotional duplicity; the discovery of a non-malignant brain tumor -- she always delivers.

Mostly, she reflects her mother's hard-won gentle honesty -- now we can understand why Anne Morrow Lindbergh spent so much time walking alone on the beach:

"I keep a journal for many reasons," writes her daughter, "but the most important one is that I want to be as honest with myself as possible. I think it is very hard to be absolutely honest with oneself, especially if words come easily. Before I write, I have to ask myself what I think, and if the answer comes too quickly, I have to stop and ask again -- Now, what do I really think. ... I would like to write more and more truthfully as I grow older."

She has done that here.

Scott Eyman is books editor of the Palm Beach Post.