Or maybe this striking fact: Some soldiers have childhood memories of when the fighting began.
A decade is longer than the time ground troops were in Vietnam, longer than the Revolutionary War (both eight years). The invasion of Afghanistan - launched about four weeks after the Sept. 11, 2001, terrorist attacks - introduced the nation to a new enemy, the Taliban, and a seemingly endless mission, the global war on terror.
For most of the decade, the war in Afghanistan was eclipsed by Iraq, where there were more troops, more deaths, more headlines. That situation has reversed in recent years as Afghanistan has captured the spotlight, with a surge in U.S. forces, a spike in violence and the killing of Osama bin Laden in neighboring Pakistan - which generated new debate about the rationale for the war.
While there are plans to wind down the war, the costs already have been staggering. Hundreds of billions of dollars. Thousands of U.S. troops injured and nearly 1,700 dead, not counting the deaths of Afghan civilians and U.S. coalition partners.
But no war can be reduced to numbers on a ledger. The real impact is measured in the widows left behind, the children who will never know fathers or mothers, the names of the fallen etched in marble memorials and a new generation of veterans with wounds, memories and lives forever changed.
THE DEPLOYED: Since the war began, more than 2.3 million troops have been deployed to Afghanistan and Iraq, as of the end of July, according to military statistics. Of those, more than 977,000 have served more than one tour and about 300,000 have been deployed more than twice.
Maj. Jeff Pickler ticks off the years one by one: 2002, 2003, 2004 ... until he reaches 2009.
For parts of eight straight years, he was at war. Four tours in Afghanistan. One in Iraq. On his first, he met some Afghans in remote villages who didn't even know U.S. forces were there - or why. On his last, he spent a grueling 15 months facing an experienced, organized enemy and on average, more than three firefights a day.
A decade into the war, Pickler says he always expected a long haul.
"When people asked me what it was like when I was going back, I'd say, 'Hey, this is something that we're not going to fix immediately'," he says. "I began to understand this is a very, very complex battlefield ... and appreciate we've got our work cut out for us."
Pickler, a West Point graduate of the Class of 2001, was in gunnery class in Fort Sill, Okla., on 9/11. When the Pentagon was attacked, he rushed to call his father, who was director of the Army staff there; the elder Pickler was not injured.
As an Army Ranger for three tours, Pickler expected frequent deployments. He spent about three years away from home and didn't hold his first-born, Everett, until he was 5 months old.
Through it all, the 32-year-old soldier says he always leaned on his faith.
"I remember a couple of operations clearing out caves ... I'm literally crawling through with a pistol in my hand. I would stop and I would say a prayer," he recalls. "That's how I handled it."
Pickler's last tour - in rugged, mountainous northeastern Afghanistan - was the toughest. "You have soldiers fighting for their lives in just really, really austere conditions," he says. His battalion lost 26 soldiers.
Returning home, he was greeted at the plane by one of his soldiers who'd lost both legs and was in a wheelchair. "You just don't forget something like that," he says.
Pickler faced family adjustments, too. His wife, Amy, had raised their son alone for a year. "She had become really independent and rightly so," he says. "I was trying to figure out how to be a dad without stepping on her toes."
But Amy also offered comforting reassurances. "She would say she wasn't sure if the husband who came back would be the same one who left," he says. "Over time, I'd ask 'What do you think?' and she'd always say, 'You're still you.'"
Now Pickler trains West Point cadets - some of whom will likely head to Afghanistan for a war entering its 11th year.
THE FALLEN: The number of U.S. troops killed in Afghanistan has jumped dramatically since 2009. As of Oct. 4, there were 1,682 deaths, according to an Associated Press count.
In Georgetown, Texas, there's a life-sized bronze statue of Sgt. 1st Class Nathan Chapman.
In Fort Lewis, Wash., there's a cul-de-sac called Chapman Circle.
In Afghanistan, there's a base known as Camp Chapman.
Chapman, a 31-year-old career Special Forces soldier was the first American to die in Afghanistan from enemy fire. He was shot in January 2002 after meeting with tribal leaders near the Pakistan border.
In the years since, Chapman's parents, Will and Lynn, have honored their son in public memorials and mourned - and celebrated - him in private.
"Over time, the pain gets a little better, then a moment will strike you when it's as strong as it ever was ... and it's as if I just heard it," says Will Chapman, a retired Air Force officer. "The loss of a child leaves a hole that you can never fill."
The Chapmans remember their son's two sides: the tender father of two little ones who joyously danced with his 2-year-old daughter at his brother's wedding, and the strong, tough soldier who'd served in Panama, Haiti and Operation Desert Storm.
After the 9/11 attacks, Chapman "was one of the first to volunteer," his father recalls. "I think his attitude was 'If you're going to war over this ... they're not going to go without me.'"
Since then, Lynn Chapman has spent time reading about and trying to understand the history of Afghanistan. "It's a very complicated country," she says. "Once we've accomplished the mission and our country's safe, we need to leave."
Will Chapman says he's a little surprised the war has continued this long but notes that his son "died doing what he enjoyed doing and what he believed in. I think he would be vastly disappointed if we didn't follow through and complete the mission that they started."
THE WIDOWED: As of May, more than 2,900 women and men had been widowed in the war on terror. That includes combat and accidental deaths, those who've succumbed to wounds later and suicides in theater. About 50 are widowers.
A decade ago, Tara Fuerst sat in her Florida high school library watching televised images of the World Trade Center ablaze.
The next year, she was at boot camp with the Florida National Guard.
In 2003, she met the love of her life, Joe Fuerst, on a field exercise. She was shy, he was outgoing. She was a novice; he'd already been on active duty in Korea and Kosovo.
In March 2005, Joe and Tara became husband and wife. By July, they were in Afghanistan.
Eleven months later, she stood in a morgue in Kandahar, holding her husband one final time, kissing him goodbye. She was a widow at 22.
Five years have passed, but Tara's memories remain vivid, sometimes triggered by small things - the scent of Joe's cologne on someone else, the strains of one of his favorite country songs.
"He's always there," she says. "He never leaves my mind."
Like all newlyweds, Tara and Joe had plans: They'd already chosen baby names and bought property in a rural area north of Tampa They'd extended their deployment so contractors could start work on their home while they were away. Tara still owns the land. "I'd never build a house on it," she says. "Those were OUR dreams."
Though they were at separate bases in Afghanistan, they talked daily and saw one another frequently.
Tara was at her computer that day, monitoring convoys and hostile activities when a message popped up on her screen: A soldier had been shot in the leg.
Then she saw the battle roster number FU8132, and she panicked: It was Joe.
She tried calling his cell phone repeatedly. No answer.
When the helicopter arrived, bringing the horrible news - Joe had been killed by a rocket-propelled grenade - she pounded her fists on a truck and fell to her knees, screaming and sobbing.
For two years, she could barely talk. She had nightmares and memory problems. She quit college, frustrated by students' complaints about boys and car troubles. It all seemed trivial.
Friends encouraged her to move on; Tara felt pressure to do so, too.
"At first I thought ... I'm going to date, I'm going to still have a family," she says. "All it did was make me miserable. It's not something that I was comfortable with. I'm in love with my husband. I'm not in love with anybody other than him and I can't pretend that I will be. In my mind, we're still married. ... I love him more each day."
In 2008, Tara attended a gathering of the American Widow Project, a support group of women with similar experiences, and she began to feel better. Her connection has become so strong that she plans to eventually leave her job with a government contractor and work for the group.
"After meeting them," she says, "I was able to say, it's OK to laugh, it's OK to have fun, there are days you can look ahead to ... and there's still a future."
LIMBS LOST: As of July, 1,439 troops had limbs amputated from injuries in Iraq and Afghanistan, according to a recent report from the Congressional Research Service. Until early 2009, Iraq accounted for most major limb losses from battle wounds in the Army. Since then, most have come in Afghanistan.
Before Nov. 28, 2006, Sue Downes was quiet and easygoing. Now, she says, "I'm more vocal."
"I just talk and talk and talk," she says. "It's a whole new life. God gave me a second chance and I'm doing my best."
Nearly five years ago, Downes, then serving with the Army military police in Afghanistan, lost both legs after her Humvee ran over two land mines. The blast killed two soldiers, both close friends, and threw her out of the truck, trapping her legs under her gunner's shield; she almost bled to death in the snowy mountains.
Downes has rebounded from her wounds and traumatic brain injury. It has not been easy.
She had to learn to feed herself. To write. To sit up. And to adjust to artificial legs.
"I actually accepted it, believe it or not," she says. "I'm a fighter. ... I knew I could walk again. When I saw my kids at the foot of my bed, they were my motivation. I knew I had to get out of there and just go."
Downes spent two years at Walter Reed Army Medical Center, undergoing physical therapy, rebuilding her strength, enduring more than a dozen surgeries on her stomach, liver, arms, legs. She also learned to balance on prosthetic legs.
"The image part of it was going to bother me the most," she says. "You've got two robotic legs sticking out of your Capris and your dress. It's not common when you see something like that in a lady."
She fretted, too, about the reaction from her kids' classmates (her son, Austin, is now 11; her daughter, Alexis is 12). She visited their school in Tazewell, Tenn., wearing her prosthetic legs. The students "were amazed. They just wanted to touch them," she says.
Downes, 31, has different legs for swimming, for high heels and for running - she can do a slow one-mile jog. She also has a service dog, a yellow Lab named Lyla, who opens doors and does household chores. "I haven't been in a wheelchair for almost three years," she says. "I hate that thing."
Downes' unit returned to Afghanistan for a second tour after she was wounded, and two soldiers who lost their legs ended up at Walter Reed, joining her in therapy. She was their inspiration.
Downes divorced after her injuries - she says it was unrelated to her wounds- and is now engaged. She's also active in veterans' aid groups. "I always believed if God wanted me to die that day, he would have let me die. He wanted me to be here for a purpose," she says.
Part of that purpose is raising her children.
"I have to be a role model," she says. "I have to be positive. I want them to look and learn from me, to know that ... it can always be worse. Always think that and you can get over anything."
WOUNDED IN ACTION; About 13,700 U.S. troops have been wounded in Afghanistan and the region as of Sept. 6. In the early part of the war - through 2005 - almost 700 troops were injured, according to military figures. But in the past four years, nearly 12,000 have been wounded.
Three years after returning from Afghanistan, Anthony Villarreal would return "in a heartbeat" if he could.
He knows, of course, that's impossible because of a 2008 IED attack in Afghanistan that left him with third-degree burns over nearly 70 percent of his body. His face is disfigured, his right hand gone, his left hand missing fingers.
He spent three months in a drug-induced coma at Brooke Army Medical Center. When Villarreal finally was able to walk, he stood before a hospital mirror, stunned by his reflection.
"I just broke down," he says. "I couldn't recognize myself. ... My brain started racing. What am I going to do? Why do I look this way? What are people going to see when they see me? What's going to happen to me?"
His ears, much of his nose and his eyebrows were burned off. He would need skin grafts to replace his eyelids and rebuild his upper lip. Villarreal spent the next two years hospitalized, enduring about 30 surgeries.
At home in Lubbock, Texas, folks would stare when he was at the store. Some would approach him. He saw that as an opportunity. "I thought if people are so curious, why not tell them the story of what happened. I can make them comfortable for other service members who come back with more traumatic injuries," he says. "It helps get me out of my shell."
So every chance he gets, Villarreal talks. To the Texas Tech football team. To a friend's eighth-grade history class. To local homebuilders. He tells people about June 20, 2008, when his Humvee hit a roadside bomb, severely wounding him and two fellow Marines. A Navy medic was killed.
At the time, Villarreal was a newlywed on his third deployment - he'd been to Iraq twice.
Villarreal, now a college student, says when some family and friends tell him 10 years of war is too long and it's time to leave, he points out all the troops have done - building schools, bridges, wells. "I like to tell people we're over there to help people and give them the things we have here," he says, "not just fight the bad guys."
In 2001, Anthony Villarreal was a 15-year-old high school sophomore, inspired by 9/11 to join the military.
At 25, he is a disabled but determined veteran trying to fashion a new life, but sometimes missing his old one.
"If I could be over there right now, I probably would be. Sometimes it makes me mad that I can't," he says. "But I did my duty. I completed my mission. Now I'm back home, resting up, I guess."