Indra Nooyi bubbles with ideas.

The uber-successful PepsiCo CEO — who in her youth attended an all-girls Catholic school in her native India and killed it on lead guitar in an all-girl rock band — has been described as “the smartest person in the room” (Jeff Sonnenfeld of Yale School of Management) and “very strong” (former Yahoo CEO Carol Bartz). And in an illuminating interview on Freakonomics Radio’s “The Secret Life of CEOs” series, released Thursday, we learn even more about her — from how she keeps the mom guilt at bay to how her chip-eating customers behave. Here are some of the most fascinating highlights.

Pepsi CEO Indra Nooyi speaks onstage at the Fortune Most Powerful Women Summit in 2017. (Photo by Paul Morigi/Getty Images for Fortune)

The vast difference in how women and men eat potato chips. Crunch on this: The genders eat chips differently, says Nooyi, who is renowned for taking deep dives into consumer behavior. “As you watch a lot of the young guys eat the chips, they love their Doritos, and they lick their fingers with great glee, and when they reach the bottom of the bag they pour the little broken pieces into their mouth, because they don’t want to lose that taste of the flavor, and the broken chips in the bottom. You know, women I think would love to do the same, but they don’t. They don’t like to crunch too loudly in public. And, you know, they don’t lick their fingers generously and they don’t like to pour the little broken pieces and the flavor into their mouth,” Nooyi says, noting that the company is looking at different packing and design for male and female consumers.

What Nooyi’s 20-hour-a-day workday looks like. When asked if it’s true that she works “20 hours a day, seven days a week” she responds: “Mm, close.” A sample day might look like this for Nooyi: Wake up at 4 a.m., read what she didn’t read over the weekend, play tennis for an hour, get into work at 8:30 a.m. and work until about 10 p.m. or midnight. Her work day includes “back-to-back meetings” and dinners with team members. She might fall asleep around midnight, and is back up again at 4 a.m. the next day.

What makes Nooyi “die of guilt:” Nooyi feels mom guilt just like the rest of us parents — and she handles it like a boss: “I’ll tell you a story that happened when my daughter went to Catholic school. Every Wednesday morning they had class coffee with the mothers. Class coffee with mothers for a working woman — how is it going to work? How am I going to take off 9 o’clock on Wednesday mornings to go for class coffee? So I missed most class coffees. My daughter would come home and she would list off all the mothers that were there and say, ‘You were not there, mom.’ The first few times I would die with guilt,” she says.

“But I developed coping mechanisms. I called the school and I said, ‘give me a list of mothers who are not there.’ So when she came home in the evening she said, ‘You were not there, you were not there.’ And I said, ‘Ah ha, Mrs. Redd wasn’t there, Mrs. So-and-So wasn’t there. So I’m not the only bad mother.’ You know, you have to cope, because you die with guilt. You just die with guilt,” Nooyi says, adding that “the biological clock and the career clock are in total conflict with each other. Total, complete conflict.”

Why Nooyi thinks we see so few female CEOs: “We get a lot of women in at the entry-level positions. As you get to middle management, you know, women rise to those positions, and then that’s the childbearing years. And when they have children, you know it’s difficult to balance having children, your career, your marriage, and you know, be a high potential out-performer who’s going to grow in the company, in an organization that’s, you know, every one of them is a pyramid. So it starts to thin out as you move up. We have to solve for that,” she says.

In her case, she had help from family: “I had lot of extended family that all chipped in to help us take care of our kids. You know, my husband and I worked in partnership with each other to make sure that our schedules didn’t keep us both out of the office at the same time. But then our families all chipped in to help take care of the kids, or supervise the nannies, if you want to call it that. And in turn, we take care of our aging parents today,” Nooyi says.

The full episode with Nooyi is available at http://freakonomics.com and all podcast providers or you can listen here: