PHNOM PENH, Cambodia — Almost every year, at least, we are reminded of the Holocaust. Seldom, if ever, are we reminded of the “Cambodian Holocaust.”

Need a refresher?

It was the mid ‘70s. It started as the Vietnam War ended, in 1975. It was a grass-roots rebellion headed by Pol Pot and it was intended to improve life for all Cambodians. It turned into four years of murder.

Until we ventured into Southeast Asia to cruise the Mekong River with AmaWaterways, what little we knew of Pol Pot and the Khmer Rouge we’d long forgotten. In more than three days on (and off) the AmaDara, we learn more than we expected…probably more than we want to learn.

The conventional wisdom has always been that the Khmer Rouge killed two million Cambodians…and Vietnamese who lived in Cambodia.

“That,” says Nyphea Khun, the articulate and intelligent tour guide hired by Ama, “is how many deaths were registered. The population of Cambodia went from about eight million to about four and a half million. What happened to almost two million people? Did they just disappear?”

There is a lost generation in this warm and now-friendly country. Children grew up without knowing how to be mothers, because they had none. Grandparents didn’t exist. The knowledge base was undermined — Khmer Rouge soldiers were instructed to kill anybody they thought was educated. A simple thing like wearing glasses was a death sentence.

We meet one educated survivor, in the small village where he lives, not far from here. His name is Oum Son Thon and he survived by pleading ignorance…more ignorance than pleading. He messed up his hair. He escaped into the countryside. He developed callouses on his hands, to look more like a worker, doing what he was told and pretending to be a simple man with no education. He told the Khmer Rouge he was a worker and didn’t know how to write.

He was, in fact, a teacher. 

Somehow he survived. By 1993, after the “outside world” came to Cambodia’s rescue, Thon returned to his village, by then a shadow of what it had been. He had one shirt and one pair of shorts. He taught, for free. Eventually, four of his students graduated from university. Today, he is 81 and he regularly tells his story to passersby, like visitors on a river cruise.

Had we not been on the AmaDara’s inaugural cruise from Siem Reap to Ho Chi Minh City, we’d never have met Oum Son Thon, who speaks no English. We’d never have met Nyphea Khun, the guide. We’d never have learned about the Cambodian Holocaust.

That would have been our loss.

Tomorrow: Prison and The Killing Fields

In the news…

• European rivers Danube and Elbe still struggling with low water levels
• Carnival promotion until Sunday: $40 to spend on board per day per room

Today at portsandbows.com: River cruising in the U.S.

Celebrity Constellation
3 nights
January 4, 2016
Fort Lauderdale (return): Nassau, Key West
Inside: $259
Cost per day: $86
www.celebritycruises.com