Taking on such massive assignments made McKenna a fixture in the upper echelons of the Fortune Most Powerful Women ranking for years. The 57-year-old would have certainly been near the top of this year’s list, published on Thursday, had she not surprised the retail world with her retirement announcement in August. Her successor, Kath McLay, previously at Walmart’s Sam’s Club chain, rose to No. 14 from No. 28 last year in part because of Walmart International’s size.

Though McKenna was long viewed as a front-runner to replace Walmart Inc. CEO Doug McMillon whenever he stepped down, McKenna says she has no desire or plans to be a CEO again, though she will remain as an advisor to Walmart Inc. And there are no indications McMillon is going anywhere just yet—the Wall Street Journal reported in March that he plans to stay on at least three more years.

In a wide-ranging interview with Fortune, McKenna shared advice for women looking to chart a similar C-suite path as well as musings on how corporate America can increase the female CEO cohort that currently makes up a mere 10.6% of the Fortune 500. She credits Walmart for giving her assignments of increasing difficulty and outside her comfort zone, allowing her to prove her mettle. But she also notes the importance of taking ownership of one’s career.

“I’ve been able to have these experiences, but I’ve had to take the leap into them as well,” she told Fortune a few weeks after stepping down.

On the employer end, she urges companies to support women with training, mentoring, and frequent feedback, citing Walmart as a model: “We put people early in their career into jobs that are probably a slight stretch for them. Fantastic. But we have to remember that’s not where it ends.”

Still, where it starts is coming under new pressure in corporate America amid a backlash against diversity, inclusion, and equity efforts. “You need the very best talent for every job. Full stop, end of story. Nobody ever wants to get a job just because of who they are. They want to get a job because of how capable they are,” says McKenna. “Regardless of the rhetoric around ESG, there is a business imperative to do this and to be diverse. The focus has to be, ‘How do we get the very best people?’”

McKenna arrived at Walmart in 2013, after 17 years at British supermarket chain Asda, which Walmart bought in 1999, and was instrumental in helping the retail giant develop its online grocery business years later. It was in that role that McKenna attracted the notice of higher-ups all the way in Bentonville, Ark., Walmart’s headquarters. After two years in an international strategy role at Walmart, McKenna was named operations chief at Walmart U.S., now a $400-billion-a-year business.

That made her the top lieutenant to former Walmart U.S. CEO Greg Foran, currently CEO of Air New Zealand, in overhauling Walmart stores to make them more inviting places to shop and support its e-commerce business, which at the time was still light-years behind Amazon. McKenna then went to Walmart International in 2018, where she was tasked with exiting some big but sluggish markets for Walmart, like Britain and Japan, a change in tack for a company that long prioritized a presence in as many markets as possible. 

McKenna also had to decipher how to make Walmart competitive in India, a notoriously tough market for Western retailers. She eventually led the biggest deal in Walmart’s history when the retailer bought a majority stake in Flipkart for $16 billion, opting for the e-commerce route rather than brick-and-mortar stores in a significant change for a company that had always pursued a stores-based strategy domestically and abroad. 

Along the way, McKenna says she learned to become comfortable with failure whenever she suffered a setback. “I’m still not particularly good at it or enjoy it, but I am more comfortable with it. If you’re not prepared to put yourself out there and take the risk, you’ll never get to the next thing,” she says.

At the same time, she notes, a CEO must instill a culture allowing for misfires and not surround themselves with yes-people. The point is not to dwell on errors but instead candidly analyze them to understand why they happened, move on, and avoid lengthy navel-gazing mea culpas. “The greatest thing that helped me was having teams who were prepared to tell me when something’s not right. If you can build a team that pushes back, you can mitigate the risk of making large failures,” McKenna says. 

Another bit of advice she has for aspiring executives is to avoid cosplaying as someone they aren’t. “When I started, I was always trying to be somebody else, always trying to fit in and finding the mold that I thought worked,” McKenna says. “One of the benefits of age is that I’ve learned to be much more comfortable and more authentic with who I am. It is easier to do once you’ve got experience.”

There were many stops and starts during her and Foran’s store renewal efforts. But ultimately, they paid off, and Walmart’s growth gained steam in the mid-2010s. Moreover, its e-commerce finally started to seriously compete with Amazon, thanks to stores better equipped for shipping-from-stores and in-store pickup of online orders. McKenna says Walmart U.S.’s refashioning is the highlight of her career. “Putting a little bit of sparkle back in and creating an environment where our associates could flourish on a personal level was quite dear to me.”

As for what’s next, McKenna insists her CEO days are behind her, and she’s taking time to figure things out. That could include some teaching since both her parents were schoolteachers. “I’m old enough to reflect on the incredible set of opportunities and the career I’ve had, and I’m young enough to write a new chapter. This feels like the right time to do it.”