By the end of this year, four of the country's most well-known broadcasters who've been fixtures on the air for decades will have signed off for a final time:

• Charles Osgood, 83, hosted his final "Sunday Morning" on CBS.

• Vin Scully, 88, called his final game after 67 years as the voice of baseball's Dodgers.

• Garrison Keillor, 74, presided over his final "A Prairie Home Companion" in June after two stints totaling 37 years.

• And in December, NPR's Diane Rehm, 80. will step away from her daily public radio talk show, also after 37 years.

I spoke with Rehm, who is the author of "On My Own" (a book about husband John's prolonged death, which led her to take up the cause of the "right to die" movement), on the eve of her milestone birthday.

Diane Rehm of NPR.

Q: Happy birthday. You've always been candid, so I want to ask: How does 80 feel? Is it just a number, or an important milestone?

A: Up to now, every decade's birthday I have felt great, absolutely terrific. And I thought: Good, next one, next one. But this one has caused me pause because, perhaps as you do, I read the obituaries every day and many, many people die in their 80s.

What is this decade going to be like? My mother-in-law said the 80s were the best years of her life. I'm going to go on that assumption.

Q: You're stepping down from "The Diane Rehm Show" by year's end. What was the tipping point that made you decide?

A: When the new general manager of WAMU [the Washington, D.C. station where Rehm's show originates] arrived, one of the first meetings I had with him, I said: "I want you to know I have decided that at 80, I'm out. It's enough, It's time for somebody new, and I want you to know I am firm in that decision."

Q: In the baseball world, David Ortiz of the Boston Red Sox had a career year at age 40. Some are asking him: Why leave now? Others say how lucky he is to be leaving on top. Do you feel like you're leaving at the top of your game?

A: I do. I really do. I've been traveling so much, and I don't say this in a self-congratulatory way, people are crying and saying to me, "What are we going to do without you? We need you. Can't you please stay on?" And I am trying to reassure people that what's coming next will serve them well.

I don't know what's coming next. I can only hope that it will serve them as well as this program has because I know that they feel they can get an in-depth understanding of such complex topics on the program. So, we'll see.

Q: Before you step away from the mic, any regrets at all, or are you at 100 percent peace with the decision you made?

A: A thousand percent at peace. Totally. I have had such good feelings in knowing what this program has accomplished. I mean if I were really, really sad, it would be because we didn't live up to our own standards. But we did. And I think we've done the best we could do. Hopefully, the next rendition will take what we have built and create something even better.

Q: Years ago, you had an excuse, if you chose to use it, to leave your show because of spasmodic dysphonia that affected your voice. I remember you saying you don't like the way you sound. You could have said, "I want to do other things," but somehow you powered through, with regular Botox treatments. So what lessons are there for others who suffer a physical setback and think all is lost?

A: John Rehm just kept saying to me: "We've got to find out what's going on. Your career is not over. You have to find out." And once I found out that I could bring my voice back to a near normal place, it seemed OK to me, as long as the majority of comments about my voice were not negative.

And when I came back, I did not know what the reaction was going to be. And it seemed to be OK and now people tell me I have the most distinctive voice on radio. Well, if they're not turning me off, why not stay?

Q: Even after doing this for 37 years, there has to be someone you've wanted to interview that you haven't been able to reel in. There's still time, after all.

A: Here's the thing. When I was the recipient of the National Humanities medal at the White House in 2014 and I went up to the platform and President Obama shook my hand and was about to put the medal on, he whispered in my ear, "You know, Diane, I was on your program before I became president," and I whispered, "Yes, sir, it's time for you to come on again." We are now in the negotiations with the White House in hopes of having the president on before I leave the program.

I would very much like to talk with him about his tenure, his decisions, his ability to persuade, his decision to not go up on the Hill and be the bash 'em-on-the-head kind of president and how he feels the presidency itself may have changed.

Q: In your book, you have a chapter titled "Who Am I?" and you wrote that "through all these years, I've defined myself as wife, mother, friend, radio broadcaster." Since you lost your husband, you're no longer a wife, and come December, you'll no longer be a radio broadcaster.

A: I may be a podcaster [with a chuckle in her voice].

Q: How do you plan to reshape your identity? What does the next chapter look like? Do you call it retirement or something else?

A: I call it a continuing journey in the mystery of life and whatever that may bring.

I never planned on this career. So I am perfectly happy to be open to whatever might come. That's the great mystery for me. I'm looking forward to whatever comes.

I'll be speaking out on the right to die, the right to make choices at the beginning of life as well as the end of life — the right to choose an abortion and the right to choose to die. We as human beings should have the right to make our own choices.

Q: One of your other pursuits, and this is fairly new, is that you've been in the play "Surviving Grace," where you portray a woman who descends into Alzheimer's. Will that continue?

A: Oh, my, yes. It is such an exquisite experience to move from a woman who's chastising her daughter for not dyeing her hair properly or wearing good makeup to one who not only loses the ability to think for herself, but loses her husband to another woman while she is in an institution. My God, to think about how often that may happen in real life. And to play that woman who was the playwright Trish Vradenburg's mother, that's exactly what happened.

And so Trish with her wonderful comedic sense — she wrote for the TV series "Designing Women" — took her own experience and created a tragic comedy out of it. Some of the lines are absolutely brilliant. [There'll be a reading of the play in Chicago next year.]

Q: You're stepping away from the mic this year with some pretty good company: Garrison Keillor and Charles Osgood. So we've come a long way from Walter Cronkite's mandatory retirement from CBS at 65. Are we more enlightened today about the value of an experienced hand at the tiller, or is this more a matter of people living longer?

A: They really are recognizing that — especially with radio and television and writers — people love what they do.

I would love to have seen "Sunday Morning's" host go on and on and on. He's wonderful, so much a part of my Sunday morning. Garrison Keillor I've been listening to for years. I remember when he signed off for the first time, years and years ago. I sat and listened to that last program and wept.

People become accustomed to voices, to people, to personas, and we are living longer, healthier, and we have a lot more to give. But we may be ready to move on to something else. Nobody should force anyone out. We ought to be able to go on as long as we feel good and the audience feels good about what we do.

Q: Others who have stepped down from high-profile jobs in the media have warned that once you're not on the air every day, the invitations will slow down, you won't be recognized as much. As someone who was in the thick of it for so long, will that be hard for you?

A: Sure, I think it will. I'm going to miss people walking up to me at the supermarket and say, "Hi, just love your program." Being in some strange airport the other day, this young man in Dallas came up to me from behind and said, "Excuse me, are you Diane Rehm?" and I said, "Yes." He started crying and said, "You have made my life." What am I going to say to him?

So sure, I'm going to miss that. We get used to being thought of as special. And that's what I'm going to miss. I hope what I do for the rest of my life will also be thought of as special and worthwhile, but in a different way.

Q: You never went to college, but have always said each day you hosted your show was part of a continuing education. What did you learn from your guests or listeners about this next chapter, about retirement?

A: A lot from Fred Rogers [PBS' "Mr. Rogers"] and from his leading a much lower-profiled life. He continued to influence by his prior example. He was such an example of a great human being.

Jimmy and Rosalynn Carter —my heavens! — what they have done and continue to do.

How could I ever think that retirement stops life? It doesn't. Life goes on. And I will go on in many different ways.

This article originally appeared on NextAvenue.com.