CONCORD, Mass. >> It can be hard to go back to a book you once adored. You do not feel like the same person, and it does not feel like the same book.

But “Little Women,” an indelibly formative reading experience for so many of us, exists almost in a category of its own. And the book’s 150th anniversary this year presents an irresistible opportunity to revisit it.

Across the country groups are holding “Little Women”-themed exhibits, conferences and lectures. Penguin Classics recently published a fetching new annotated edition, with a foreword by the singer/writer Patti Smith, one of the book’s vast army of admirers.

A new film is in the works, directed by Greta Gerwig and starring Emma Watson, Meryl Streep, Timothee Chalamet, Saoirse Ronan, Laura Dern and Bob Odenkirk, right on the heels of a BBC miniseries last year. Not that the book has gone unfilmed before. Actresses who have depicted the book’s heroine, Jo March, in various cinematic iterations through the decades include Katharine Hepburn, June Allyson and Winona Ryder.

Where there are lovers of “Little Women,” so there are lovers of talking about their love for “Little Women.” In July, a small crowd of academics, experts and enthusiasts convened for a discussion of the book at the place officially known as Louisa May Alcott’s Orchard House, down the road from the center of Concord, Mass. This shabbily genteel house is where Alcott and her family lived from 1858 to 1877, and where she wrote and set “Little Women.”

In the audience was Mika Shingai, a 32-year-old receptionist, who was introduced to “Little Women” as a child when her mother read it aloud to her. The book spoke to Shingai’s sense of adventure and fueled her youthful inclination, she said, “not to be too much of a girlie-girl.”

There was Cathlin Davis, 44, a professor of education in California, who said Alcott’s work had made her feel less alone at a delicate time in her childhood, teaching her that the way she felt — as an “outsider on the edge” — was not just fine, but actively desirable.

Time has not attenuated her enthusiasm. “My claim to fame is that I have 100-plus copies of ‘Little Women,’ ” she said.

“Little Women” was that unusual thing, a classic that is also an instant hit. It was wildly popular from the moment it was published, in two parts, starting in 1868. (The second part, in which the loose ends left by the March sisters’ unmarried states are neatly tied up, was written in response to the success of the first. It came out the following year and has proved dismaying to readers who prefer Jo’s unmarried independence.)

The book was also revolutionary, in its way.

“At the time, ‘Little Women’ was the most real book about women that had ever been written,” said Anne Boyd Rioux, a professor at the University of New Orleans and the author of the recently published “Meg, Jo, Beth and Amy: The Story of Little Women and Why it Still Matters.”

Having delivered a popular talk at Orchard House, Rioux was expanding on her themes over breakfast at a local inn. “These are real people, flawed characters that are not meant to be moral exemplars, but people that readers can identify with,” she said.

Before “Little Women,” young people’s books were mostly preachy tales in which the virtuous were rewarded and the wicked punished. Girls, particularly, were little more than dull collections of moral qualities, pawns in authors’ lofty allegories.

The four March sisters are deeply human — trying to be good but forever getting into scrapes provoked by their particular character flaws: Jo’s hotheadedness, Meg’s vanity and Amy’s shallowness. (Beth has no faults, unless you count pathologically insipid self-abnegation.)

The book, especially in its creation of Jo — independent, unconventional, irreverent, impatient, devoted to her writing and proud of her ability to earn money at it — has been an inspiration and a model. Jo has always appealed to tomboys, rebels and freethinkers, her passion for creativity providing aspiring writers with a glimpse of how to operate in the world.

Most readers reserve their softest spot for Jo. “I, personally, am Jo March,” novelist Barbara Kingsolver once wrote. Writer and filmmaker Nora Ephron and her sister Delia, an author, both said the same thing (“technically” Delia said, if it really came down to it, she was more Jo-ish than Nora).

“‘Little Women’ offered the first glimpse of a life defined by talent and inclination, not simply marriage,” author Anna Quindlen wrote. Feminist organizer, writer and social political activist Gloria Steinem said it was a place of comfort and encouragement during a scattered childhood. “Amy, Beth, Meg and Jo — who was probably why I became a writer — were my family and friends,” she said.

The appreciation is not universal. American author, scholar and critic Camille Paglia has described the book as “a kind of horror story,” seeing its sentencing of Jo to marriage as an unhappy capitulation to social convention. Nor is the British novelist Hilary Mantel a fan. “How I despised her, with her preposterous literary pretensions!” she wrote.

The book also has a new poignancy in light of what we know about its author’s own ambivalence about her status as a woman. Many friends and acquaintances wrote later of “how much she acted like and wanted to be a boy,” Rioux writes — much, of course, like Jo herself.

Jo’s straightforward wish to live like a boy, behave like a boy and speak like a boy also feels different in 2018, given our better understanding of gender identity. And it makes her eventual marriage to Professor Bhaer seem more than ever to be an ending dictated by the literary marketplace and societal norms rather than by Alcott’s own predilections.

Alcott herself remained unmarried. She was fierce on the topic.

“I’d rather be a free spinster and paddle my own canoe,” she wrote.

Books speak directly to readers, of course, and everyone’s response is his or her own. For Diane Duray, part of the Alcottian enthusiasts’ group in Concord in July, “Little Women” has been one of the great influences of her life.

“When I was 8, I wanted to be Jo, and I also wanted to be in public policy and government,” said Duray, who did just that, getting state government jobs in Ohio and New York before becoming a community college professor. (Now retired, she continues to teach classes to senior citizens. She has not grown tired of discussing “Little Women.”)

She is 65, but the book lit a fire inside her that has not gone out. “I’m still Jo,” she said.