Why is ‘Tuck Everlasting’ so beloved? Now I understand.

Natalie Babbitt’s “Tuck Everlasting” isn’t a long book. Its just-published 50th-anniversary edition runs well under 200 pages, and a dozen of these are devoted to an introduction by novelist Gabrielle Zevin, a short memoir by Babbitt’s daughter, Lucy, and an appendix reproducing some of the book’s w...