"Everyone was his best friend. And that was his personality. He could make everyone feel important," his mother Lisa told CBS News correspondent Mark Strassmann.
The born Marine was the first child of police lieutenant Steve Xiarhos and wife, Lisa.
"We were so proud - proud he wanted to do that and serve our country, especially be a Marine," Steve Xiarhos said.
But Xiarhos was also a son of Yarmouth, Massachusetts, his grieving Cape Cod hometown.
Last July, the 21-year-old Marine corporal was.
The pain of Nick's death even reached President Obama. As he weighs whether to risk more American lives in Afghanistan, Nick has become the president's face of sacrifice.
"And also the cost of freedom," his father said.
CBS News first met Nick Xiarhos back in January as part of another story.
That story was about a suicide truck bomb attack in Iraq. In the explosion, two Marine guards died saving dozens of their buddies, including Xiarhos.
He was humbled by their heroics.
"To be able to save all of us and in turn sacrificing themselves, that's what makes the difference," Nick said at the time.
In February, President Obama saluted that bravery.
"These two Marines stood their ground," Mr. Obama said.
Xiarhos was there. He met his commander-in-chief.
And he switched units for the chance to fight again.
"I remember when he first called me and said he was going to Afghanistan. And I'm like, 'oh, no,'" Lisa Xiarhos said.
Three months later, Xiarhos came home for the final time. He had been killed by a roadside bomb.
"I'm the proudest but also the saddest man in the world," Steve Xiarhos said.
The kid from Cape Cod died answering his country's call to service. When President Obama learned a young Marine he had met had been killed, he asked to meet Nick's family.
"It was instant connection really," Steve Xiarhos said. "He basically said that when he makes decisions, he thinks about brave men and women like Nicholas. We want freedom and success to protect our country and help others, that's what we do, we're Americans. But the cost is huge."
A cost paid by an outgoing young Marine.
A cost the president promises to remember.