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, Timothée Chalamet, Saoirse Ronan and Laura Dern, right on the heels of a BBC mini-series last year. Not that the book has gone un-filmed 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.