FORTUNE — With Jay Leno hosting, more than 600 friends—Al Gore, former U.S. Senators Sam Nunn and Tim Wirth, Spanx founder Sara Blakely, and his date, Colorado environmentalist Sally Ranney, among them—helped Ted Turner celebrate his 75th birthday on Saturday night in Atlanta. The guests dined on bison filet—fitting since Turner owns 55,000 of the creatures. With his five children and 13 grandchildren in attendance, Turner sang “My Old Kentucky Home,” and recited Shakespeare (Richard II on integrity: “Mine honour is my life, both grow in one; Take honour from me and my life is done”) from memory. He earned a standing ovation, and it was a reassuring performance from a man who has worried his friends as much as fascinated them lately.
When I heard last summer that Turner’s physical health and memory were slipping, I asked for an exclusive interview with the man whose accomplishments exceed those of most any other businessman: Turner created CNN, built a media and sports empire, won the America’s Cup and acquired more land than any other person in the world—well, until another billionaire, cable TV titan John Malone, picked up a few more acres to surpass him. I had written two Fortune cover stories about Turner: in 1997, after he committed to give $1 billion to help save the United Nations from it’s financial troubles, and in 2003, when he was facing his own financial disaster. Turner lost more than $8 billion when Time Warner stock collapsed after the company’s merger with AOL . The story, titled “Gone with the Wind,” detailed how this man prone to tragedy (his sister died at age 17; his father killed himself at 53) lost his job at Time Warner and the love of his life, Jane Fonda, in addition to his billions of dollars in personal wealth.
Since that story a decade ago, I had seen Turner a few times but not sat down with him for an interview. When I recently went to Atlanta to talk with him for the Q&A that appears in the current issue of Fortune (the “Businessperson of the Year” issue, now on newsstands), I found him to be calmer than he used to be, more reflective and not quite as cantankerous (he called me a “yoyo journalist” only once). Irrepressible, Ted Turner remains one of the most uninhibited, candid and authentic bosses you will ever meet. Here’s our conversation:
How are you feeling about life at 75?
It’s better than being dead.
How’s your health?
It’s okay, but it’s not great. I have both sleep apnea and atrial fibrillation, which are both debilitating conditions.
You have a pacemaker?
I do. I had it put in a few months ago. I have two. I feel a little better. But I still get exhausted real easily.
How would you describe yourself today at 75 compared to Ted Turner at 50?
I had more energy at 50. On the other hand, at 75, I’ve probably got a little more wisdom and good judgment than I had at 50 because I’ve got more experience. But I haven’t really changed. I’m still driven by the same philosophy.
And what is that?
Well, we need to make a lot of changes in order to survive another 50 years. We’re in a lot of trouble. For one thing, we’ve got thousands of nuclear weapons on hair-trigger alert. An accident or an earthquake could cross wires and off we go. And that would be the destruction of the world. If the Russian nuclear arsenal was fired at the United States and other targets and we fired back at them with thousands of nuclear weapons, it would be the end of life on earth.
Ted, I interviewed you for a Fortune cover profile called “Gone With the Wind” 10 years ago. In 2003 you said to me, “I think the chances are fifty- fifty that humanity will be extinct in 50 years.” Do you still believe that?
Fifty years aren’t up yet. I’d say that’s generally the case. The nuclear threat is the most imminent threat. But global climate change and environmental destruction of the earth and our resource base, that’s the other great threat. It works a little bit slower, but it would still work at a 50-year time frame very possibly.
Read the rest of the Q&A by subscribing here. And watch Turner talk about his biggest regret: