The Man Who Shouldn't Be Alive: US Army Soldier, Blown Up 7 Times, Still on Patrol Staff Sgt. Chad Joiner continues to risk his life for country, family.

GHANZI, Afghanistan July 4, 2013 -- He remembers each and every one.

The shockwaves, the sulfur penetrating his nostrils, the thick, toxic smoke sifting into his lungs, and the burning desert sand flying into his vehicle.

He remembers the sudden jolt -- fully alert one second, then panic-stricken and deaf the next. He remembers the pain, the smell of burned flesh mixed with metal, and the frantic search -- with his hands, in the dark -- desperate to find fellow infantrymen in the hail of gunfire.

But most of all, while he is out on patrol in Ghazni, Afghanistan, 31-year-old Staff Sergeant Chad Joiner remembers one thing:

"I'm still here," he said, smiling. "I'm enjoying life."

In America's longest war, Joiner has a singular distinction -- and it's not his purple heart. Over the course of his four deployments -- three in Iraq and the current one in Afghanistan -- Joiner has survived not one, not two, but seven improvised explosive device blasts.

In other words, he's been blown up seven times. And he's still alive.

"For the normal person, it's mind blowing," he admitted. "People don't understand it."

In each case, he was driving in a vehicle when the bomb exploded directly underneath him.

"I can remember the first night that we got hit, and nobody knew what was going on. We were going through a palm grove just outside of Ramadi, in Iraq," Joiner said.

"It was just a huge explosion, nobody knew what it was. Everything on the radio was confusion, everybody started firing in all directions because nobody knew what it was. It was just crazy."

ABC News travelled to a remote region in Eastern Afghanistan, close to well-known Taliban strongholds, to tell the stories of American soldiers who aren't part of the war's drawdown, soldiers who continue to risk life and limb every day to keep the Taliban at bay. Although NATO's role in the war has officially shifted away from active combat towards advising and training Afghan soldiers, thousands of Americans are still in harm's way.

Americans like Joiner.

Joiner's story is resoundingly all-American, if not slightly cliché. Born and raised in Cody, Wy., a small town with a population of just 10,000, he married his childhood sweetheart straight out of high school.

He had never thought of a career in the army, but enlisted in the days following 9/11, intent on doing something to avenge, in his words, the "sucker punch" felt by millions of Americans.

Within two years, he was on his first deployment to Iraq, when the first IED exploded.

"It's nothing like you see in the movies," he said. "You see the flash, then you hear this loud, hollow boom. It shakes your whole body. It shakes you to the core. You feel the compression, you feel the shock wave. Dirt flies, rocks fly, all kinds of stuff fly around. It sucks all the air out. You're deafened for a time period, confusion, ears ringing. You get that sulfur, that smoke smell."

Joiner's tone grows serious as he describes the various experiences, outside Baghdad, near Ramadi, and in Iraq's famous Sunni triangle. One blast was so serious it put him in rehab for six months, as doctors diagnosed him with Traumatic Brain Injury or TBI.

Through it all, Joiner never lost sight of his goal -- to serve his country. There were many times when he could have called it quits, but he kept signing up for new deployments.

He said there is a reason why he's still alive, "God has a plan for me."

"There's an obvious reason why I'm still here," Joiner said. "I don't know what it is yet, but there's a reason why He is keeping me around."

"Nightline" was with Joiner in Afghanistan, gearing up for another mission: To find and remove all roadside bombs from Highway One, a key thoroughfare that links Afghanistan's two biggest cities: Kabul and Kandahar. As the war winds down, thousands of American troops will rely on this highway for safe passage out of the country.

"They realize that when they get out of that truck," Captain Clinton Winland explains, "Every step could be their last."

As Joiner climbs into an armored vehicle, part of the 20 or so vehicles forming a convoy that will travel several hours on the road, it's easy to think he's crazy -- some kind of adrenaline junkie with a death wish.

But he's about as normal as you can get. On the road, he admits there are days he'd rather be at home, walking the dog and having a barbeque.

"But we've got a job to do out here," he said.

So how does one of the luckiest men in Afghanistan continue to stay alive, even after being blown up seven times?

"Nightline" travelled with Joiner on the mission, where coalition troops discovered a massive, roadside bomb. An explosives disposal team sent in a robot to dismantle it, but before the robot could, the bomb exploded, just meters away from where Joiner stood.

And that was just the beginning.

Find out what happens to Joiner and his unit during their mission in our "Nightline" report.