On the outside, Michelle Obama appeared confident and self-assured as first lady of the United States in one of the harshest spotlights in the world.

On the inside, she was dealing with a “fearful mind” she said she’s lived with for 58 years.

“It is everyday practice to silence the ‘no’ in your own head, the thing that is telling you, ‘don't try that new thing,’” Obama told "Good Morning America" co-anchor Robin Roberts in her first broadcast interview about her highly-anticipated new book, "The Light We Carry: Overcoming in Uncertain Times.”

"I too have had to learn to wrestle that fearful mind down," Obama said.

In "The Light We Carry," which will be published Nov. 15, the former first lady opens up about dealing with anxiety – and shares the tools she has learned to use when she’s feeling disquieted.

PHOTO: Robin Roberts speaks with former first lady Michelle Obama for the ABC special, "Michelle Obama: The Light We Carry, A Conversation with Robin Roberts."
ABC News
Robin Roberts speaks with former first lady Michelle Obama for the ABC special, "Michelle Obama: The Light We Carry, A Conversation with Robin Roberts."

Obama recalls the moment her husband, former President Barack Obama, first approached her about running for president. She said he told her, "I won’t do it unless you’re in."

"Wasn't that a hard thing he put on my lap?" Michelle Obama said. "My fearful mind said, 'Oh no, he must be crazy.’'"

Watch the 20/20 special “Michelle Obama: The Light We Carry, A Conversation with Robin Roberts” on Hulu.

In her new book, she writes how "strange" it is that her "fear" could have altered history.

PHOTO: Former First Lady Michelle Obama and former U.S. President Barack Obama embrace at a ceremony to unveil their official White House portraits at the White House on Sept. 7, 2022.
Kevin Dietsch/Getty Images, FILE
Former First Lady Michelle Obama and former U.S. President Barack Obama embrace at a ceremony to unveil their official White House portraits at the White House on Sept. 7, 2022.

"By the time my husband approached me with this big question, I had practiced moving myself out of my comfort zone,” said Michelle Obama, who said it was her past experiences that helped her be "comfortably afraid," as she writes in her book.

"I left my neighborhood and went to a magnet high school. I left my city to go to an Ivy League school. All of it was uncomfortable. All of it. Had I looked and listened to my fearful mind, I would have said, ‘No, I'm just gonna stay put. This is safe,’” added the former first lady.

Michelle Obama also said she had thought about the type of example she wanted to set for her two young daughters.

"The rational me said, 'We can do this. We know how to do hard things. We've done it before,'" Michelle Obama said. "We could afford to take the risk. And what story would I tell my kids? That their father had a chance to do great things and to help a lot of people, but I as their mother said, 'No' because I didn’t want to change?"

The importance of friendships

Michelle Obama also writes in her new book about how living in the White House impacted one of the most important parts of her life: her friendships.

"One of my most important tools is what I call, ‘my kitchen table,’ the cabinet of good friends beyond my family who are each other's cheerleaders," said Michelle Obama. “When I became first lady of the United States, I realized I have a choice. I can either close up, no new friends, or I can find a way that, even in this odd position, to reach out and find new people in my life."

PHOTO: Former First Lady Michelle Obama speaks onstage at the Clooney Foundation For Justice Inaugural Albie Awards at New York Public Library in New York, Sept. 29, 2022.
Dimitrios Kambouris/Getty Images, FILE
Former First Lady Michelle Obama speaks onstage at the Clooney Foundation For Justice Inaugural Albie Awards at New York Public Library in New York, Sept. 29, 2022.

A few friends Michelle Obama gathers around her "kitchen table" include her friends Dr. Sharon Malone and journalist Michele Norris, who she calls her "D.C. homegirls," and her longtime Chicago friend Sandy Matthews.

Matthews said the women talk about everything "A to Z."

"I love it, because we start with where we are, you know, and how we're doing and how we're feeling and where we're going," said Matthews.

The kitchen table is also a place for new friends to gather.

One of Michelle Obama's "newer" friends is Denielle Pemberton, who recalled the first time she met the first lady.

It was during the first year of the Obama presidency and Pemberton's daughter was invited over to the White House for a playdate.

"You get a call that says, 'The first lady would like to invite your daughter over for a playdate ... We need your social security number, we need your license," Pemberton told "GMA."

Obama recalls the memory in her book, writing, "Years later, when we could laugh about it, she told me that knowing she’d be driving the family car. She had gone out and gotten it washed. She’d also gotten her hair done. And her nails. Never mind that the instructions had made clear she wouldn’t be setting foot outside the car."

Pemberton said that years after their first meeting, the former first lady remains a friend who likes to "bring people together."

"She feeds off of the energy of people and companionship and camaraderie, and competition," said Pemberton.

"The Light We Carry" will be published on Nov. 15, 2022, in 14 languages and 27 countries around the world, according to the book's publisher, Crown, an imprint of Random House.

Like she did with her bestselling memoir “Becoming,” Obama will go on a book tour for “The Light We Carry,” during which she’ll be interviewed by celebrities including Oprah Winfrey, Tracee Ellis Ross and Tyler Perry.

Obama will kick-off the tour Nov. 15, in Washington, D.C., before heading to Philadelphia, Atlanta, Chicago, San Francisco and Los Angeles.

Watch the 20/20 special “Michelle Obama: The Light We Carry, A Conversation with Robin Roberts” on Hulu.