As a young Army platoon leader in Vietnam, Max Cleland sent hours of audio dispatches home to his parents not knowing just how true his words would become.
"I'm definitely coming back a little bit differently than when I came here," he said on tape.
On April 8, 1968, just days from the scheduled end of his tour in Vietnam, Cleland spotted a hand grenade in the grass as he jumped off a helicopter. It had been dropped by another soldier, and Cleland reached for it, not knowing it was live.
In a flash of fire, Cleland lost both legs, his right arm and, almost, his life.
Watch Cleland discuss his struggles in the military and political arenas Saturday evening on "World News." Check your local listings for air time.
Click here to read an excerpt of Cleland's book, "Heart of a Patriot," in PDF form.
He quickly found the answer in public service, improbably winning a state Senate seat. He went on to head the U.S. Veterans Administration under President Jimmy Carter and become Georgia's secretary of state.
In 1996, when he was elected to the U.S. Senate, Cleland was confident he was well past the greatest test of his life. But he wasn't.
Now 67, Cleland has just emerged from a battle he says was far more bruising.
"I went down into almost a death spiral," Cleland said, looking back. "I didn't try to commit suicide, but I didn't want to live."
Cleland's descent began after he lost a bruising battle for re-election to Republican Saxby Chambliss in 2002. Losing was tough enough, but the way he lost added to the pain. Chambliss' campaign questioned Cleland's "courage to lead" in a campaign ad that flashed pictures of Osama bin Laden and Saddam Hussein.
Cleland's Battle With Post-Traumatic Stress Syndrome
With his defeat, the life Cleland had constructed for himself crumbled. He lost everything -- his job, his office, his income, his fiancee and, ultimately, his purpose in life.
"I did -- absolutely everything that was meaningful to me, except my life. Just like Vietnam," he told ABC News.
The experience, he added, "Swallowed me whole."
Cleland was diagnosed with post-traumatic stress syndrome, a remnant of his ordeal in Vietnam nearly 40 years ago suddenly was triggered by losing his Senate seat and life as he knew it.
Cleland has just written about his harrowing ordeal in a new memoir, "Heart of a Patriot." Rarely has a politician ever been so open about the personal toll of losing public office.
"Losing my race for re-election was having a profound effect on me. Another grenade had blown up in my face -- this time on the political battlefield rather than the military battlefield," he wrote.
"The election was just like the grenade. Over and done in an instant, with no appeal. No, we can't put your life back together again. No, you can't have your limbs back. No, you can't have your Senate seat back. That life is over now."
He returned to Walter Reed decades after his first stint as a patient there, this time for treatment of post-traumatic stress syndrome and depression. There, he discovered soldiers being treated for wounds from the war in Iraq -- a war he had voted for as a U.S. senator, a vote he now regretted.
Playing on television screens at Walter Reed was the inspirational video Cleland had starred in as a senator to help the newly injured returning from war.
"The irony was overwhelming," he said. "I mean, you know, because I could see myself saying those things and they were great and accurate at the time, but I hadn't received the second wound, the second Vietnam, the second loss of sense of meaning and purpose and direction in life.
"I would look down the hall," he added, "and I would see a younger generation, you know, missing arms, legs ... and I thought, 'Oh my God.'"
Obama Names Cleland Secretary of the American Battle Monuments Commission
Through medication, therapy and the help of longtime friends, Cleland has recovered from the long-simmering pain. Ironically, Cleland benefitted from some of the same assistance for shell-shocked veterans that he himself pushed for as head of the Veterans Administration.
"Depression is a real thing. I mean, it takes you over. It takes over your life. And I mean, I don't want to ever, ever, ever go through anything like that again. Never," Cleland said. "And thank God for the grace of God and the help of friends and the people at Walter Reed who counseled me through it and some medication which I am no longer on but was on for a while. So, you know, I was lucky to survive all of that -- just like Vietnam."
This year, President Obama appointed Cleland as secretary of the American Battle Monuments Commission, the federal agency responsible for overseeing monuments and cemeteries in 25 foreign countries honoring the 125,000 U.S. servicemen and servicewomen buried overseas and the 95,000 U.S. forces missing in action as a result of foreign wars.
By being able to honor the fallen and their sacrifice, Cleland said he sees his life coming full circle.
"Now, I'm charged with helping to provide a sense of meaning and purpose ... that matches my own search for meaning," he told ABC News.
"Archibald MacLeish, who lost a brother in World War I who is buried in Flanders Field, said this in a wonderful poem: 'We give you our death, give them their meaning.' So it is really up to us, the living, to provide that meaning for those who have given their all for this country. And that is the way I look at it, that is the challenge that I have," Cleland said.