Mr. Diing's brief foray into education was cut short when his uncles and brothers died of starvation during the trek, along with thousands of other "Lost Boys of Sudan," children who fled on foot from the civil war that raged for nearly 20 years.
But the significance of the early lessons stuck with Diing, now a resettled refugee living in Buffalo, N.Y. He earned his high school degree in Kakuma, a refugee camp in Kenya, and later completed undergraduate and master's programs in western New York. He's currently working toward a doctorate degree in education.
Diing is trying to spare more than 3,000 children in South Sudan from his experience. They now attend the two-year-old New Hope Primary School, a project of Diing's Buffalo-based nonprofit group Aid and Care for Africa.
Just 21 teachers and five administrators preside over the school. Students from 22 villages in Diing's home state of Aweil walk miles to reach the school, often with empty stomachs and the fear of meeting wild animals in forests they must cross through.
"We told parents that this is a dangerous situation, that their children could end up being attacked by lions," Diing recalled. "But the parents say, 'My kids staying in the village without education will be just like that, anyway – death.' "
Some 55 percent of the students are orphans, living with foster families. They include 10 of the 34 children Diing sponsors himself and his mother looks after. The remaining 24 live with two of his sisters in Kenya and Uganda, where they can receive care for various ailments.
In total, Diing supports about 50 people aside from his mother, including his deceased father's seven other wives.
"I live a simple life here," says Diing, speaking at a buffet restaurant near his tiny apartment just north of Buffalo's downtown. "But it's the same as my friends do – the little amount we make, we share."
Diing allocates 15 percent of his monthly income to support Aid and Care, for which fundraising has been difficult. He hopes to construct a sister secondary school by 2015 and is aiming to raise $400,000.
Diing is a bouncy, exuberant man who is never known to complain, says Gerry Catalano, a programs coordinator at Niagara University's college of business administration. He sits on the board of Aid and Care along with Mr. Angello.
Diing casually recounts the deaths of his friends and family members. He rolls up his pants to reveal delicate pink scars running up and down his dark legs – the result of stumbling into sharp tree limbs and bushes during his exodus from Sudan.
But when he reflects on the 400 Buffalo public school students he now counsels in his job as an academic coach for Journey's End Refugee Services, a community-based organization that provides support to refugee families in western New York, his tone hardens. Diing is mystified by the dangerous situations some youths put themselves into in this city, which has the third-highest percentage of low-income residents among all large American cities.
"Some kids are wilder than they used to be before they came to America," Diing explains. "They rebel. They get stressed.... Last year, there was a 17-year-old boy from Burma who came to school with a gun.... It's like, 'Why would you lead a risky life when you live in a safe place, with no attacks, no hunger, nothing?'"
It's hard for him to fully understand, he says, when he compares inner-city Buffalo with refugee camps in Africa.
"I always tell them my experience of carrying a gun as a child," says Diing, recalling his time in the Sudan People's Liberation Army, a rebel group. He was forcibly recruited as a soldier after fleeing Kakuma. The 16-year-old was shot and wounded just two weeks into service but managed to escape back to the camp.
"The kids say to me, 'Wow, you've been through this?' "
Diing has become "very sought after" as a coach by parents and children, says Donna Peppero, an educational services coordinator for Journey's End. "He is such a child in spirit, and I think he is finally able to have that childhood again that he was stripped of during his childhood years."
This summer, Diing will meet the roughly 3,000 students at New Hope in South Sudan for the first time. His visit will coincide with the country's pending establishment as a new, independent nation, the result of a 2005 peace agreement between the North and South and a referendum vote in favor of independence in January 2011.
Diing plans to return regularly to South Sudan to oversee construction of the secondary school. It will include a library, computer lab, and dorms for volunteers.
They will be welcomed. He expects that the school will need all the help it can get.
• Visit www.aidandcareforafrica.org