I've interviewed presidents, prime ministers, celebrities and superstars, and it's been a privilege to talk to them all. But I'm not sure I would put any of them on a par with a man called Arthur Seltzer, a man whose story is as inspirational as it is humbling, the story of an ordinary man who did extraordinary things.

Not that Arthur was alone in his endeavors. He was one of tens of thousands of young Americans who on June 6, 1944, took part in the D-Day landings, an unprecedented invasion that took so many lives, but ultimately saved the world from being crushed under the Nazi jackboot.

Arthur, 84, of Cherry Hill, N.J. has only recently begun to talk about his traumatic experiences, and only then because his granddaughter unwittingly forced him to. She was doing a school project on the Holocaust and asked him if he knew anything about it. Arthur knew more than his granddaughter could have imagined. She wrote about his experiences and got an "A" for her assignment. She then called Arthur and told him she had told her teacher he'd be happy to come in and talk about his experiences. Arthur was terrified, not of standing in front of a class full of kids, but of reliving some of the most horrific memories of his life in public. But, being the man that he is, he couldn’t let his grand-daughter down, so he stood in front of them and told them the story he is now also sharing with FOX News, the story of what he calls "the longest day of my life."

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On June 6 1944, Arthur Seltzer, then just 19 years old, a communications specialist with the 4th Signals Battalion, was attached to a unit of the 29th Infantry. As they approached Omaha Beach at dawn the men on Arthur's landing craft signed a dollar bill — 36 signatures, a signal of their bond, a lucky dollar in Arthur seltzer's pocket. Minutes later they were in the water.

"We were in the 3rd and 4th wave going in," says Arthur, "and we were told not to go out the front of the ship but to go over the side of the ship so I had 60 pounds of equipment on my back, soldiers had their stuff and so over the sides we went. I can't swim. I wasn't worried about getting shot, I was worried about not drowning. When we finally got to the beach there was no craters for us to hide in and naturally machine guns up there were firing. Omaha got the name 'bloody Omaha' because the only thing you could see was soldiers lying on the beach that were dead, blood all around you."

I asked Arthur what thoughts were going through his head as he waded through the blood-red water and on to the beach, also littered with the bodies of his dead comrades.

"Well basically I believe each one was trying to say where can I go to be saved, where can I hide, where can I be that I won't get hit."

His main objective, he said, was simply to stay alive.

Arthur did stay alive, and later on that fateful day he saw the sergeant whose idea it had been to sign the dollar bill, a dollar bill Arthur has kept to this day.

"He says, 'You and I are the only two survived from that landing craft,' and I said to him. 'You mean you lost your whole squad?' and he says, "Yes I lost my whole squad."

Arthur Seltzer's war did not end on D-Day. He went on to fight in the Battle of the Bulge, forever known as the greatest battle of the war, and on April 29, 1945, Arthur, who is Jewish, was with the American troops who discovered the Dachau concentration camp.

Arthur describes the scene as, "Dead bodies all around, naked skeletons, people dressed in these uniforms with black stripes, they were half starved, the odor was so bad you could hardly take it. The odor of death."

Six and a half decades on, Arthur still suffers from post traumatic stress. But he's learned to talk about his experiences, to pause when he needs to, to relieve the tension by pulling at a rubberband he wears on his wrist, something he did regularly during our hourlong conversation.

When I asked him how he deals with these anniversaries he became particularly emotional.

"Every June 6 the first thing I do is put my flag out." Arthur then paused, clearly struggling with the memories. "That's very important to me. It's a bad day for me." At this point he stopped, the tears began to flow and he pulled at the rubber band. Eventually he gathered himself and said simply, "It brings back a lot of memories."

But Arthur Seltzer also told me he is ready to move on. "It's a different generation." I asked him whether we should forgive but not forget, to which he replied, "That's correct. You never forget any anniversary, you don't forget the friends you lost when you served over there you don't forget the people who gave their lives to make this country a free country."

Arthur Seltzer is not just an American hero, he is a world hero. As someone born in Britain I could have been born into a country where German was the first language, where Nazis ruled, had it not been for the efforts of Arthur and so many Americans like him. On this anniversary I owe him, and every D-Day veteran, a huge debt of thanks. We all do. To steal NBC anchor Tom Brokaw's book title, they truly are The Greatest Generation.