When Tim O’Brien, the celebrated author of “The Things They Carried” and other works drawn from his time at war, was 58, he became a father for the first time. Two years later, son Tad joined firstborn Timmy, and O’Brien felt a new weight on his shoulders.

“I want to tell you about your father, the man I think I am,” he writes in the first chapter of “Dad’s Maybe Book,” a memoir that grew out of 15 years of random notes. He started intending “to leave behind little word-gifts” for sons who he feared would not get to know him well.

This loving gift to his now-teenage sons is sprinkled with literary criticism, writing tips, thoughts on his relationship with his father and philosophy on aging and mortality: “Birth is a death sentence,” he writes. “We know this, but we don’t want to know.”

He records with delight and pride signs of his boys’ wit and sensitivity. He wanted “to yell ‘I love you, I love you’ with every stroke on this keyboard.” And he has.

He hopes that when he’s gone his boys will read widely and critically, and that they will write, so he includes instruction — read these books, honor these rules — and essay questions. (“Will you ever go to war?”) He also provides a clear look into his own approach to writing fiction and the blending of fiction and fact.

Though he claims not to think much about Vietnam, the war is everywhere in these pages. He gives Tad and Timmy a history lesson on Concord and Lexington — from the perspective of the British and American “grunts” who marched and fought and stood or ran in terror and died in those opening skirmishes of the American Revolution, and he draws parallels with what he and other soldiers in Vietnam endured — and endure. In his imagination today, half a century after his war, he digs himself a trench at night, a foxhole, to sleep in.

As he turned 70 in 2016, thoughts that came at 3 a.m. took on “a distinct summing-up quality,” and he fretted about the failures, “numerous and decisive.” But in age he also finds another “redeeming virtue” that recalls moments in Vietnam, after the “humping” and fighting, the dying and nearly dying. “When you’re almost dead, things sparkle. What is taken for granted in peacetime, as in youth, suddenly becomes so precious it makes you cry. … You come to value things that never before had such crushing value.”

Chuck Haga is a former Star Tribune reporter who lives in Grand Forks, N.D., and teaches media writing at the University of North Dakota.

Dad's Maybe Book
By: Tim O'Brien
Publisher: Houghton Mifflin Harcourt, 381 pages, $28.
Event: Talking Volumes, Oct. 16, Parkway Theater, Mpls. Sold out.