For Eugene Heacock, who served aboard a landing craft during World War II, it was memories of combat near Naples, and the carnage at Iwo Jima.
For Ronnie Arond, it was recollections of the ward for spinal injuries at a military hospital on Staten Island that made her pause.
As Memorial Day approached, veterans of America's bloodiest war remembered last week those who gave their last full measure.
"I saw people who were so seriously shot up and near death and dying when I was on the beach," said Heacock, 90, of Southold, who served aboard a landing craft both during the invasion of Italy and during the evacuation of wounded Marines from Iwo Jima a year later. "One guy asked me 'Do you think I'll ever play football again?' but I really don't know whatever happened to him. When you lose that many men, you can't keep track of them."
About 50 World War II veterans from Long Island visited the World War II Memorial in Washington and other monuments a week ago. They were guests of Honor Flight, a nonprofit organization that has been providing World War II veterans with visits to the bowl-shaped war memorial since 2005.
Arond, a former Army nurse, was among the veterans there. Now a Bellerose resident, she enlisted in early 1945 and was on staff at Halloran General Hospital as American troops wounded in Europe poured into the Army medical facility.
"It brought back a lot of memories that I hadn't thought about for years," Arond, 91, said of her tour of the World War II monument, an oval courtyard cradled by granite columns marked with bronze sculptures and stone engravings.
"I could picture the hospital wards," said Arond, who was in her early 20s and married to an Army soldier -- still her husband today -- when she enlisted. "I can still remember one or two faces, even though it was so long ago. They had head wounds, body wounds, fractures, just about everything you could think of a person who was wounded in battle."
Originally known as Decoration Day, the roots of Memorial Day extend back to the 1860s, when localities began marking the graves of their Civil War dead, according to the U.S. Department of Veterans Affairs.
"In Flanders Fields," a 1915 poem that mentions red poppies nodding among rows of grave markers in a military graveyard, led to the association of the crimson bloom with Memorial Day.
It was not until after World War I that Memorial Day celebrations were expanded to commemorate the dead of all American wars. In 1971, Congress made Memorial Day a national holiday, to be observed on the last Monday of each May.
In all, more than 1.3 million American servicemen and women have perished in wars dating to the American Revolution.
"This Memorial Day brings great satisfaction that we were able to subdue these countries that were very vicious in their attacks on innocent countries and innocent people," Heacock said.
But victory came at great cost, he said.
"I saw men that were flying up in the air, hit and blown up," he said.
For Joseph Abbondondelo, 91, of Melville, Memorial Day brings memories of one of them: a tall Ohioan who was a crew member aboard the B-24 Abbondondelo flew on bombing runs over southern Europe during World War II.
Now a retired bank teller, the Roslyn native had trained with the Ohioan, who Abbondondelo remembers as Donald Tisinger, before they had gone off to war together.
They were gunners and had shared the adrenaline-fueled tension of trying to drive away buzzing waves of German fighter planes during the dozens of missions they flew together.
The last time he saw Tisinger was on June 26, 1944, when their plane was shot down during a raid on an oil refinery near Vienna.
"He was with the original crew I went over with, the crew I flew most of my missions with, and we trained so often together I would say we were family," said Abbondondelo, who was scheduled to make the Honor Flight trip, but was unable to attend. "You kind of take those things hard when they happen."
For many of the dwindling number of World War II veterans who are still alive, Memorial Day is personal.
"The tail gunner has the best view, and he said Tisinger did make it out of the plane, but after that, nobody really knows," said Abbondondelo, who spent the duration of the war as a prisoner at Stalag Luft IV, in northern Poland.
"We were at a loss," Abbondondelo said. "He just didn't make it to the ground."