I spoke to Gloria Steinem, Mandy Patinkin, Alan Alda, and other celebs about what makes them tick. Here are my favorite answers.

When Carl Reiner was 28, he co-wrote and acted on "Your Show of Shows" with Sid Caesar. He then got the idea to write a situation comedy based on his own family life. The series, which became "The Dick Van Dyke Show," ran for five years and won 15 Emmys. In the 60s, Reiner and his friend Mel Brooks began doing a comedy sketch at parties. Reiner was the straight man and Brooks was the 2,000 Year Old Man who had 42,000 children — and not one of them ever came to visit. Reiner also directed Steve Martin in "The Jerk" and "Dead Men Don't Wear Plaid." At 97, Reiner is one of the oldest celebrities on Twitter. He tweets every night.

"I check the obits in the morning. If I'm not in it I'll eat breakfast. But now I look at the obits differently. I used to look to see how old people were you know and usually they're much younger. Instead of getting upset by it, 'I say beat you. I got you beat.' Every once in a while there will be a 100-year old. I say, 'You win.'"

Reiner also does something else every morning. He walks around the block in his Beverly Hills neighborhood, singing a song that Bing Crosby recorded called the Tumble Down Shack in Athlone.

Reiner sings:

"I'm a long way from home and my thoughts ever roam to ould Erin far over the sea. There's a bright gleaming light guiding me home tonight down the long road of white cobblestone. Down the road that leads back to that tumble down shack, to that tumble down shack in Athlone.

"That's it," he says. "I've got to go back to work."

Hear more from Carl Reiner on the joys of being old.

In the 1970s and 80s, Norman Lear was the king of television, creating one hit series after another including Sanford and Son, the Jeffersons, and All in the Family. Two years ago, Lear, who is 97, sold a new show to NBC about adventures in a senior community. In 2019, Lear made Emmy history when his show, Live in Front of a Studio Audience, was nominated for Outstanding Variety Special, making Lear the oldest person ever nominated for an Emmy. ABC has renewed Lear's Special for two more installments.

"I have been getting up every single day for 95 plus years and doing the same thing. Looking forward when I go to sleep to the taste of coffee the next morning. I make a big deal out of breakfast. I love breakfast. I usually have a thin slice of bagel with some smoked salmon and a large salad. So a lot of people think 'Oh, he has a salad. That's why he's feeling good.'"

Do you get terrified of dying?

"No, I don't. I don't wish it and I started to say I'm not looking forward to it, but I am in the sense that some questions will be answered. Even if there's no question answered, that's an answer. Sorry, no more questions. It's just another long sleep."

Hear more from Norman Lear on one possible secret of living a long life.

Sixty-six-year-old Mandy Patinkin plays CIA officer Saul Berenson on "Homeland." He's also an Ambassador for the International Rescue Committee and every season when he finishes shooting "Homeland," he goes to a refugee camp to try and help the people who are living there.

"I would not have learned any of those things that I know today at this moment without the struggles I faced earlier. I didn't get to pick and choose in a candy store exactly how to be and behave. My nature was just what it was. I did the best I could. Sometimes it wasn't what I wished for. But I got to live long enough, thank God, and I got to have great children and a great wife and great friends. And great opportunities and great teachers. And then I got cancer, you know, in 2004 and I don't wish anyone to get cancer but it sure makes you look at the sunrise and sunset differently. It sure makes you look at every day since that diagnosis in a very different way. You want to make the most of it. You want to be better if you can. Not just to make the cancer go away, just not to waste the day and the precious time you have."

Hear more from Mandy Patinkin on embracing his struggles.

Eighty-three-year-old Alan Alda worked as a waiter and a clown before landing the role of Captain Hawkeye Pierce, a surgeon in a mobile unit in the Korean War. "M*A*S*H" lasted for 11 seasons and became one of the biggest TV hits ever. Alda helped start the Alan Alda Center for Communicating Science at Stonybrook University, which has trained more than 10,000 scientists and doctors to better communicate. He's been married to his wife Arlene for 62 years.

"If you really want to communicate, pay attention to me. The essence of communication is when you think of me rather than you. What's happening in the other person's head is more important than what's happening in your head. You have a message. If you just spray the message at me I'm not going to get it. You have to get into where I live. You have to be aware of what's happening to me. Conversation is a partnership. It's a democratic process."

Hear more from Alan Alda on how to communicate.

Eighty-year-old Sheila Nevins spent 35 years at HBO, where she made more than 1,100 documentaries and won 65 Emmy awards. She's the author of "You Don't Look Your Age" where she reveals that she's had an eye lift, two face lifts, and "enough Botox to detonate Iran." Nevins wears leg warmers all year round.

"I followed the recipe of my time. The recipe of my time was to use what you were given to get what you want. I didn't sleep with a million bosses. Anyway, they're all dead. But I would say that I did not turn away advances. I really never turned someone down. I would say 'Oh, please don't.' I did the little baby thing or 'I'm going to tell your wife.' I followed the rules of the day. The rules of the day were to accept it, to comply with it and to be a little girl. I think I perfected the little girl voice. Instead of saying I'm a woman and get your hands off, I perfected that little girl voice."

How did you move on with your life after you left your job?

"The exit was extremely painful. The weaning off the job was torture. It was torture. But once I walked out the door, the air was clear. I think that I actually should not have died at my desk. I did think I would. I did think that was the place to die. And I'm not dying so fast. But I would say that I've accepted the fact that I'm a temporary resident. I'm on loan from eternity."

Hear more from Sheila Nevins on how she thrived in a male environment before the #MeToo era.

Carole Zimmer is the host of the award-winning podcast "Now What?" Curated conversations with people you want to know. (Subscribe for free here.) She's a journalist with more than 30 years of experience working in radio, television and digital media including Bloomberg News, NPR and NBC. Her work has also appeared in the New York Times, the Washington Post, New York Magazine, and other publications. She has received numerous awards including an Edward M. Murrow award for her radio documentary, "Stalking a Silent Killer." You can find more of her work at carolezimmer.com.