This theme probably isn't too much of a shocker, since Hiroshima is structured around the memories of six survivors of the bombing of Hiroshima during World War II.
Some—for example, Mrs. Nakamura—seemed to prefer not to be stuck in their memories and just want to move forward with their lives/future, while others (Mr. Tanimoto) felt that looking into the past was pretty important in order to ensure any kind of future. Since Hersey takes the trouble to delve into all these people's memories of the attack (and return to them 40 years later to get updates), it seems like he probably felt that remembering things was pretty dang important.
Questions About Memory
Why does Hersey focus so much on the memories of six people rather than taking a broader approach? What does using individual memories achieve?
Some of the subjects seen inclined to want to remember the bombing, while others don't. What attitude does the text as a whole seem to take? Is trying to escape memory a good or bad thing?
What is your reaction to the way Hersey positions himself in relation to the memories he relays? Does he seem reliable? How do we know?
Chew on This
While not getting mired in the past helps you move on, Hershey's book suggests that memory—or, put differently, an awareness of history—is absolutely crucial to preventing future tragedies.
Hersey establishes himself as a reliable purveyor of other people's memories only by putting in objective facts/info/stats.