It’s the best spring ever, green and lush, and baby robins are chittering in their nest in the maple tree and the smell of blossoms is in the air — and yet we dour Scots cannot forget that April 27 was the anniversary of our ignominious defeat at the Battle of Dunbar, our good King John stripped of his regalia, and the Stone of Scone hauled off to London. Yes, I know that 1296 seems like a long time ago, and maybe 714 years is a wee bit long to be grinding our teeth over a bad day on the battlefield, but we Scots nurse our resentments carefully. I know I do.

Plenty of people have said nice things to me over the years that I vaguely remember, but I remember with stunning clarity where I was sitting in algebra class when my classmate Cliff Nordstrom reached over and put his thumb and forefinger around my wrist and told me that I had skinny arms “like a girl’s.” The moment burns in my memory 52 years later, a permanent wound in my life. I still feel self-conscious wearing short-sleeved shirts.

Ditto, a dozen other small slights. To you they’d seem minuscule. A review of a book of mine, mostly favorable, but one sentence was like a shiv between the ribs, and that is the sentence I remember. Even in the green miracle that is spring, the memory of that sentence stings.

It’s resentment, I think, that lights a fire of ambition in our tails and drives us to beat our wings on the porch screen, hoping to reach the incandescent glow of fame and fortune.

And now I wonder what deep-down resentment the late Stephen Ambrose was nursing that motivated him to lie about his closeness to his biographee Dwight D. Eisenhower and claim to have spent hundreds of hours with Ike when, in fact, according to a close examination of the general’s daily diary, Mr. Ambrose probably spent no more than four or five.

When the story came out in The New Yorker last week, I felt ill. I admired the man. I loved “Citizen Soldiers,” about the Battle of the Bulge. He was a deservedly best-selling historian (“D-Day,” “Band of Brothers”), the prolific author of books on Lewis and Clark, George A. Custer, the transcontinental railroad, the Civil War, biographer of Eisenhower and Nixon: Why did the gentleman need to stoop to such a pitiful petty lie? And why did he lift passages from other writers and use them without quotation marks? Did someone make fun of his lack of erudition, growing up in Whitewater, Wis.? Did he feel inferior to his doctor dad? A longtime smoker (who died of lung cancer in 2002), maybe Mr. Ambrose was given to tempting fate and playing with fire.

Plagiarism is suicide. It stems from envy, I suppose, or in Ambrose’s case, the rush to produce books in rapid succession, but no matter, it’s a stain that peroxide won’t lift out. All your hard work over a lifetime, blighted by the word “plagiarism” every time somebody writes about you. It’s in the third or fourth graph of your obituary, a splotch on your escutcheon.

Here, dear reader, I must disclose that I have repeatedly lied about my closeness to General Eisenhower and have claimed more than once to have been his aide aboard the cruiser Memphis where he observed the D-Day landing from the porthole of his cabin where he was ensconced with Marlene Dietrich, sipping champagne, as I sat outside the door strumming “Lili Marlene” on a HarmonyTone F-4 mandolin.

Years later, an eagle-eyed reader blew the whistle, pointing out that HarmonyTone’s F-4 mandolin was not manufactured until 1947. Also, that I was 2 years old at the time of D-Day. Also, that Marlene Dietrich was in Hawaii at the time, canoodling with John F. Kennedy.

Luckily for me, the expose came out on the very day that President Nixon resigned, and so it got buried in the back pages, along with the embarrassing fact that my book, “Sailing With the General,” contained large swatches (unattributed) of Tolstoy’s “War and Peace.” Thankfully, these embarrassing disclosures never got in the way of my friendship with President Eisenhower, and he and I golfed many, many rounds together, at Augusta and Burning Man and Plum Creek, with George S. Patton and Walter (Old Iron Pants) Cronkite, the memory of which the smell of plum blossoms brings back with startling clarity.

Garrison Keillor is the author of “77 Love Sonnets,” published by Common Good Books.