Some must read Books: Librarians recommend the books According to Every Age.
Ages 40-49:
As they near life's halfway point, Mrs. Dalloway offers the middle-aged a second chance to reflect, the NYPL librarians say. The novel takes place in a single day, as a 50-something named Clarissa Dalloway looks back on her life and the choices she's made. She questions her marriage to Richard Dalloway and imagines life had she gone with an old flame, Peter Walsh, who reemerges later in the book.
Ages 50-59:
Emotional satisfaction isn't the only part of growing old.Physical health matters, too. The librarians recommend Light on Yoga to help people stay limber as their lives may grow more sedentary. The ancient practice may also help calm any feelings that a mid-life crisis is creeping closer.
Ages 60-69:
Originally published in 1953, the librarians say A Good Man Is Hard to Find is still required reading for the newly-crowned senior citizen. It's a collection of short stories that look at daily life with a kind of morbid curiosity, but also detachment. As people age, they start to look at their life and others' with a similar mindset. Your own mortality starts rushing into focus and minor tragedies may start to look rather benign.
Ages 70-79:
Better late than never to reexamine everything you thought of the world you inhabit. In The Accidental Universe, Lightman juggles two competing tendencies that everyone seems to deal with on a daily basis: the assumption that everything is permanent, and the reality that nothing is. The librarians recommend the book because new, difficult thoughts shouldn't be confined to the young.