While eating dinner in his village in southern Sudan one night in 1987, John Bul Dau had a premonition that something was amiss. Several hours later, he awoke to the sound of gunfire and bombs going off as government troops raided his village.

Dau, one of the “lost boys” of Sudan, spoke to an audience of about 30 in Harvard Hall last night, telling stories of his flight from war-torn southern Sudan, his travels in East Africa, and his emigration to the United States.

The raid that displaced Dau occurred in the midst of the Second Sudanese Civil War, a conflict between Sudan’s northern Arab government and non-Arab forces in the country’s south that ended in 2005.

After fleeing his village in distress, enduring extreme hunger and thirst, and weathering ambushes by Arab troops, Dau eventually reached a refugee camp in Ethiopia, he said last night.

There, Dau explained, he became an informal leader among a group of as many as 200 boys, all refugees who had fled the violence in Sudan.

In 1991, when civil war brought a pro-Sudanese government to power in Ethiopia, Dau’s group of boys were forced to relocate once more. After a brief return to Sudan, they moved to another refugee camp in Kenya.

In 2001, a refugee aid organization selected Dau for resettlement in Syracuse, N.Y. Dau said he and his fellow refugees did not know what to expect across the Atlantic Ocean.

Once in the United States, Dau had trouble adjusting to a completely different way of life.

Sometimes, he said, that “culture shock” took a comical turn.

When a Catholic charity group in Syracuse brought Dau to a supermarket, he was puzzled by the green salads on display.

“Why do they have this grass here?” he remembered asking. “There are no cows.”

Once resettled in Syracuse, Dau worked several low-paying jobs for companies such as McDonald’s and UPS.

He was profiled in a 2006 documentary film about the lost boys of Sudan, “God Grew Tired of Us.” Earlier this year, Dau published a memoir of the same name.

Dau is now pursuing a degree at Syracuse University as a part-time student, and he directs a nonprofit devoted to Sudanese refugee issues and rebuilding southern Sudan.

Last night’s talk was followed by a reception at Uno Chicago Grill in Harvard Square to raise money for building a hospital in Dau’s hometown.

The talk was organized by IMPACT, a subset of the Harvard International Development Organization.