COLLEVILLE-SUR-MER, France — Most were little more than boys when they fought in one of the greatest battles in modern history and turned the Nazi tide.

And now they are back.

At the 75th anniversary celebrations of the D-Day landings — the largest ever amphibious and airborne invasion— returning World War II veterans are treated like rock stars by tourists and locals.

“Thank you for your service,” most say as they shake hands at the surrounding landing beaches and the American Cemetery, the resting place for 9,387 Americans. Others simply say, “Merci.” Many ask for selfies with the old warriors.

President Donald Trump paid homage to the many fighters who lost their lives and honored returning World War II veterans at a ceremony Thursday morning. Addressing the assembled veterans, he said: "You are the pride of our nation. You are the glory of our republic. And we thank you from the bottom of our hearts."

President Emmanuel Macron of France gave a speech honoring the Allies' effort. In a short section in English, he said: “We know what we owe to you, veterans: our freedom. On behalf our nation, I just want to say thank you.”

President Trump greets D-Day veterans Thursday on the 75th anniversary of the Allied invasion at the American cemetery in Colleville-sur-Mer in Normandy, France. Carlos Barria / Reuters

One of the veterans highlighted in Trump's speech was Arnold Raymond “Ray” Lambert, 98, who has been feted more than most. As a medic in the 16th Infantry Regiment of the Army’s First Division, he was among the troops that landed on Omaha Beach. They faced especially vicious resistance, and within hours German guns had wounded or killed thousands. Lambert was one of those wounded, but who nonetheless fought to save and shelter fellow soldiers.

He shrugs off the bravery he showed that day.

Veteran Ray Lambert, 99, in Normandy, France on Wednesday. Lucie Mach / for NBC News

“We knew that in order to stop Hitler and get rid of the evil things he was doing, we had to fight,” Lambert told NBC News at a small ceremony in his honor in the town hall of Colleville-sur-Mer on the eve of Thursday's celebrations.

He believes it’s important for people to remember what his generation sacrificed.

“I would like people to remember that we grew up in a time when it was a real Depression,” he said. “We freely went to war. We went to war to protect our mothers and fathers and families and country.”

Lambert is one of a tiny handful here. Some 170 veterans of the Battle of Normandy returned for the celebrations, up to 40 of whom crossed the beaches or landed on June 6 that year.

Alvan Markle III, 100, who served as a captain in the 266th Field Artillery Battalion and landed on Omaha Beach, did not want to remember for decades.

“I did my best to forget, and now they all want to learn about it,” he said as he looked out over Omaha Beach during a tour organized and paid for by the World War II Museum in New Orleans.

Alvan Markle III, 100, a former lieutenant colonel, returned to Normandy for the 75th anniversary of D-Day. Lucie Mach / for NBC News

There are many horrors that have stayed with Markle, from the horses that pulled German artillery to the rooms in Buchenwald concentration camp where victims were hung from hooks. Bloody patches showed where men and women in their death throes scratched into the plaster. There is one thing he really wants the world to remember.

“We have, I hope, learned what can happen to a country like Germany with its wonderful talents if their worst people are allowed to be in control,” the resident of Bryn Mawr, Pennsylvania, said. “It could happen in any country.”

While this is likely the last major ceremony honoring living veterans of D-Day, younger generations are getting the message.

Jackson Allaman, 18, from Atlanta, made the trip especially to honor his great-uncle, Walter Allaman, who died in Normandy, and lay flowers at his grave.

“It is important to honor those who have served, specifically those who died in combat because they were willing to risk everything in order to protect their homes and the ones they love,” said Allaman, who traveled to Normandy with EF Educational Tours. “They also fought … to protect the lives of people they have never known.”

American military veterans in Omaha Beach in Normandy, France, on Wednesday. Lucie Mach / for NBC News

American veterans are held dear by locals in Normandy too, and the small towns and villages are festooned with American flags. Patrick Thomimes, the mayor of Colleville-sur-Mer, where the Normandy American Cemetery is, put it simply: “We are very thankful for the Americans who gave up their youth for our freedoms.”

Peter Orlando, 97, is on first trip back to Normandy since he served as a radioman aboard a tug that dragged stuck landing ships off Omaha Beach, making room for troops to land, and rescued troops and ships that needed it.

Veteran Peter Orlando with a photo of himself during WWII.

He says he took up smoking a pipe to combat seasickness, but is not comfortable being thanked for his service, flirting and cracking jokes with well-wishers. “I didn’t kill anybody,” he said during a visit to Ponte du Hoc, between Omaha and Utah beaches, where the Americans landed.

But he was still on the battlefront — and it was terrifying. “I was so scared I didn’t even know my name,” he said.

“You don’t live through something like this and …” Orlando added, pausing while wiping his hands deliberately. “You always remember.”