"He was an old soul. He was 30 years old, but he had been around. He was a forward observer. He killed people and he did it well, but he did it like no one I had ever seen. He would always ask: 'Are these really bad guys?' He wasn't like a lot of the guys over there -- not just gung-ho," said Krakauer, who left Afghanistan the day before Monti was killed and who dedicated his new book to the soldier.
As a boy, Monti was never one to give up quickly. A natural athlete, but one of the shortest boys in his school, Monti tried out for basketball every year, but never made the team. The coach finally relented when he was a senior and Monti quickly became the team's high scorer.
"Jared was not a person of great stature. The army says he was 5-foot-6, but he wasn't a lick over 5-foot-4. He was always discriminated because of his height, so he'd have to work harder than everyone else," said Paul.
"Two things were the measure of his life: No matter what, give 100 percent and never, ever give up. You could see both of those things in his final act. No matter how much was coming from enemy, he was not going to leave his comrades behind."
Just before his 18th birthday, his father signed his papers and Monti joined the Army reserves. At the time he told his father that he knew his family couldn't afford to send him to college, but later Paul found a diary in which Monti admitted that it was seeing an uncle dressed in a crisp naval uniform that inspired him to enlist.
Just after he turned 18, Monti left for basic training in 1993 in Missouri. It was the first time in his life that he had left Massachusetts.
As a young soldier he got into his share of trouble, including a bar fight with a sergeant in Kansas. As he got older, his officers recognized he had what it took to lead men.
And his men loved him for a certain disregard of the rules.
"He was always very respectful, but always had this devilish grin, like you knew he was up to something," said Tom Greer, a retired captain who Monti served under in South Korea in mid-1990s.
"He was pretty unique. Very focused, a great sense of humor, but always dedicated," said Greer who remembered Monti's enthusiasm and the seriousness with which he did things like march and drill.
Though technically a forward observer, whose primary job was to scope out enemy positions and call for airstrikes, in Afghanistan Monti found himself being called on to play a host of roles.
"He was great with the Afghans, so some captain would pull him to negotiate with the Afghans – who just loved him. He was great with new guys, so he'd be pulled to break in new guys," said Krakauer.
"He was not an impulsive guy. He was calm under pressure. But he also had this really cool anti-establishment streak. He'd be on a three-day mission and wouldn't shave, wouldn't blouse his boots. He was fit and he liked to show anyone he could keep up and kick their ass," said Krakauer.
In the weeks he spent with him, Krakauer said he was most impressed by Monti's ability to quickly size up a situation.
On patrol one day, a beat-up Toyota came barreling towards them and a young private trained his rifle on the Afghan driver and ordered him to stop. The car didn't stop. Monti ordered the soldier to drop his weapon and stepped into the road. The Toyota stopped and was searched and the driver went on his way.