The collective literary experience certainly has its benefits. Reading with a group can feed your passion for a book, or help you understand it better. Social reading may even persuade you that you liked something you thought you didn’t.

There is a different class of reader, though. They feel that their relationship with a book, its characters and the author is too intimate to share. “The pursuit of reading,” Virginia Woolf wrote, “is carried on by private people.”

Ms. Stead remembers having had especially intense feelings about books when she was young. “For me, as a kid, a book was a very private world,” she said. “I didn’t like talking about books with other people very much because it almost felt like I didn’t want other people to be in that world with me.”

Particularly with the books we adore most, a certain reader wants to preserve the experience for reflection, or even claim the book as hers and hers alone. Lois Lowry, an author of books for children and a two-time winner of the Newbery for “Number the Stars” and “The Giver,” said she recently read that Katherine Paterson, also a two-time Newbery winner and now the national ambassador for young people’s literature, had named “The Yearling,” by Marjorie Kinnan Rawlings, as the most influential book of her childhood. “I felt a twinge of ‘no fair, that’s mine!’ ” Ms. Lowry said. “I hastily backed off from that feeling because I know and love Katherine, and it’s O.K. that we share the same book.”