And because of those first-hand horrors experienced in battle, many soldiers and veterans spend Memorial Day a bit differently than the average American might.
Take Capt. David Danelo, author of "The Return" and a Marine Corps Infantry officer who served in Iraq. "I'm proud to be a civilian and I'm proud to be a Marine."
In honor of Memorial Day, Danelo talked to Legacy.com -- telling the site for Memorial Day he not only remembers his fallen comrades, but goes to visit the graves of those who may have been forgotten. "There's one cemetery in Philadelphia that has a Civil War veteran who I'll go see. He's long been forgotten and nobody thinks about him. ... I just walk around there and pay my respects to [his] memory."
The "Flags In" tradition is another way a lot of soldiers commemorate Memorial Day -- placing flags on the graves at Arlington National Cemetery.
"It's kind of an emotional process to know, 'cause I feel connected to each one of these soldiers that served before me. So It's kind of like a brotherhood thing. ... We just want to take care of our brothers and sisters. Make sure they look good," Pfc. Michael Samuel told USA Today.
But still, at least for wounded retired Staff Sgt. Luke Murphy, there is a feeling that civilians could make more of an effort to pay respects to fallen soldiers.
In a CNN op-ed piece Murphy gave an emotional account of losing friend and fellow service member Sgt. 1st Class Jason Bishop while serving in Iraq.
Murphy wrote in part, "When soldiers die, they don't just roll over and quit like in the movies. They fight like hell. ... And sometimes they lose. The biggest loser is the family, though. ... The next biggest losers are the guys who were with the soldier. Many times they've got survivor's guilt. ... So, what do nonfamily members and nonveterans think about on Memorial Day? Sometimes I think they just don't give a damn."
He suggests that people who want to show respect for members of the military could make a donation to organizations like Homes for Our Troops. That's the program that built Murphy and his family a new home that is accessible for someone with his injuries.
So however you choose to spend Memorial Day, whether by the pool or at a parade -- just try to remember why the holiday exists.