To be honest, Douglas Brent Hegdahl III had a fairly inauspicious beginning for someone who ended up being a rather brilliant intelligence gatherer for the U.S. Navy.

Hegdahl grew up in the small town of Clark, South Dakota and enlisted in the Navy after high school. After boot camp in San Diego, he got orders to the USS Canberra which was assigned to patrol the Gulf of Tonkin in the South China Sea off the coast of Vietnam.

Hegdahl’s battle station was the aft ammunition handling room for the five-inch guns, located aft, deep in the bowels of the ship. One morning before watch, he decided to take a breath of fresh air on the deck before manning his station.

Once on deck, the 20-year-old was knocked overboard by the blast from one of the ships five-inch guns.

Hegdahl floated in the South China Sea for 12 hours before being picked up by Cambodian fishermen, who turned him over to North Vietnamese militiamen.

He was clubbed with rifles for a few days, and then transferred to the infamous “Hanoi Hilton” prison.

In a genius move, Hegdahl figured his best strategy for survival was to convince his interrogators he was too stupid to be any threat. He pretended to be illiterate. He managed to convince his captors that he needed new glasses. Hegdahl’s Forrest Gumpian demeanor and youthful appearance earned him almost free rein of the camp. The Vietnamese nicknamed him “The Incredibly Stupid One” and gave him the job of sweeping the cell block courtyard— even around the front gates of the prison itself. In the afternoon, he’d sweep the courtyard during the guards’ afternoon break, monitored by only one sleepy peasant guard.

Hegdahl would hum and sweep until the guard fell asleep. Then, he’d quietly back up to a truck in the yard, spin the gas cap off and put a small amount of dirt in the tank. He reportedly incapacitated five trucks that way.

One of Hegdahl’s prison cellmates, Lt. Cmndr. Dick Stratton recalled, “Doug Hegdahl, a high school graduate from the mess decks fell off a ship and has five enemy trucks to his credit. I am a World Famous Golden Dragon [VA 192] with two college degrees, 2000 jet hours, 300 carrier landings and 22 combat missions. How many enemy trucks do I have to my credit? Zero. Zip. Nada…Who’s the better man? Douglas Brent Hegdahl, one of two men I know of who destroyed enemy military equipment while a prisoner of war.”

But that wasn’t even his most brilliant move.

From his first cellmate, Air Force officer Joe Crecca, Hegdahl learned 256 names of other POWs at the Hilton and how to memorize the information to the tune of “Old McDonald.”

Eventually, Hegdahl earned early release – not because he wanted it, but because his by his senior officer, Lt. Cmndr. Dick Stratton, ordered him to take it.

Released in 1969, Hegdahl was able to recite the names of the 256 men who were shot down or captured in North Vietnam, along with their dog’s name, kids’ names, and/or social security numbers. He testified to the torture and mistreatment of the POWs. Within days of his testimony, treatment of prisoners improved.

Because of his sweeping detail outside the prison, he was even able to tell U.S. intelligence where it could be found within the North Vietnamese capital.

In his memoirs, Stratton wrote of him, “The Incredibly Stupid One,” my personal hero, is the archetype of the innovative, resourceful and courageous American Sailor. These sailors are the products of the neighborhoods, churches, schools and families working together to produce individuals blessed with a sense of humor and the gift of freedom who can overcome any kind of odds. These sailors are tremendously loyal and devoted to their units and their leaders in their own private and personal ways. As long as we have The Dougs of this world, our country will retain its freedoms.”