A crucial element of a successful morning show is the impression that the hosts sitting behind the desk really like the audience and each other. When that impression breaks down, when viewers detect tension — or worse — they often revolt, and ratings slide (see: Jane Pauley and Ann Curry).

No such indignity befell Katie Couric during her 15 years as the reigning queen of morning television at the “Today” show. Cheery, prepared and endlessly good-natured, Couric became America’s Sweetheart.

But that was not the full picture. Couric warns early on in her new memoir, “Going There,” that as much as people thought they knew her, they saw only a “neatly cropped version.” Though she seemed so familiar, even undergoing a colonoscopy on air, she writes that “real life — the complications and contradictions, the messy parts — remains outside the frame.”

Couric attempts to fill in those messy parts, to demystify herself and the world she inhabits. What readers learn is that behind that chipper veneer there was a sharper-edged, savvier figure quietly taking notes — and judging everyone.

If she is attempting to prove that she is not as nice as her on-air persona, she succeeds.

Her descriptions can be unsparing. As a 22-year-old desk assistant, she spots the legendary United Press International White House correspondent Helen Thomas, whom she describes as “looking like a harried housewife in a sea of men.” CNN founder Ted Turner delivers slurred speeches and appears “to be three sheets to the wind.” It took “prison time for Martha [Stewart] to develop a sense of humor.” Prince Harry reeks of cigarettes, and alcohol seems to “ooze from every pore.”

If Couric’s memoir settles scores, it also forces her to reckon with her past self. Looking back at her old interviews, she finds that she has a lot of explaining to do. She cringes when she examines some of her choices, like when she repeatedly highlighted White crime victims rather than Black ones, or the cutthroat “booking wars” between dueling shows that racked up “professional wins and losses as a result of so much violence and misery.” She admits to censoring part of Justice Ruth Bader Ginsburg’s criticism of Colin Kaepernick because she was a big RBG fan and wanted to protect her from “a blind spot.”

She excavates skeletons, including those in her family tree, which is “blighted with racists” on one side and holds nearly hidden Judaism on the other. Her grandfather gifted her father with a first edition of “The Clansman: An Historical Romance of the Ku Klux Klan,” with a glowing inscription to “never destroy” the book. Her first husband, Jay Monahan, was a fan of the Confederacy and Civil War reenactments; Couric honored this with an Old South-themed 40th birthday party for him. He would die two years later of colon cancer, a death she mourns to this day, even as her daughters continue to struggle with his legacy.

Couric, now at retirement age, feels like she’s writing from a bygone era. She started her career in the time of “The Mary Tyler Moore Show,” “transfixed by the ambitious, independent heroine setting out for a career in TV news.” Her reaction: “Gee . . . I want to turn the world on with my smile too!”

And she did. Couric’s rise begins during her early years at ABC News, where she encountered media boldfaced names such as Sam Donaldson, Brit Hume and Carl Bernstein, who was the new D.C. bureau chief seven years after breaking Watergate with Bob Woodward.

She moves to the nascent CNN, where, after an on-air appearance, the president of the network calls Couric’s boss to say “he never wants to see you on air again.” The lesson she took was not that she should find another profession but that she just needed to practice this one a bit more.

She moved to Atlanta to work as an associate producer but never gave up the dream of being on air. She visited a voice coach to learn how to speak with a deeper tenor.

An early hero is Pauley, a “Today” show co-host. Couric writes of attending an industry black-tie dinner where her knuckles thrillingly grazed Pauley’s gown. Afterward, she and her colleague went home and French-braided their hair just like Pauley’s.

But her real North Star is her father, who had to give up print journalism for a more lucrative profession in public relations to support the family. Couric writes lovingly about how she was always trying to impress him and to use her success as a way to make up for his forced departure from journalism.

Her ascent occurs against a backdrop of constant, casual sexism. She recounts the time as a young CNN staffer when Larry King came on to her — “The lunge. The tongue. The hands.” She writes of a superior at CNN who said in front of a group that she was successful “because of her determination, hard work, intelligence, and breast size.” (Couric wrote him a memo demanding an apology, which he grudgingly provided.)

Later, at NBC, after she rose to co-host the “Today” show alongside Matt Lauer, Couric writes that “salacious tales about who was shagging whom were practically part of the news cycle.” Women had to navigate: “Some cheerfully deflected advances, defusing the moment with humor. Others willingly participated, having flings for the fun of it, a no-harm-no-foul mentality. Some leveraged the situation, accommodating a supervisor’s desires for the sake of their careers. Still others objected and risked being marginalized, demoted, even fired for some cooked-up reason.”

Throughout, Couric balances her success as the upbeat gal on the morning show with her craving to be taken seriously. Her desire to impress her father and make her mark never escaped her and eventually led her to become the first female solo anchor of a nightly news broadcast, at CBS News.

There, she encountered what she describes as real, career-blunting sexism. She reserves particular ire for the now-disgraced Jeff Fager of “60 Minutes,” with a “receding hairline and puffy eyelids,” whom she describes as cutting her out of big stories and undermining her at every turn.

By this point, Couric had long been uber-wealthy, her life buffered from reality by live-in help, cars and drivers, and fame. But her failure to hold onto her serious journalism job at CBS News left her dejected and defeated. She moved to a short-lived syndicated talk show, then to Yahoo and then later to the safety of her own production company.

Toward the end of the book, when Lauer was ousted from NBC and the “Today” show amid allegations of sexual harassment and assault, Couric professes confusion about the beloved co-host she knew and the sexual predator she was reading about. These pages are a navigational challenge for Couric, as she threads her way through reputational land mines that she barely escapes. But with Lauer protected all around by professional sycophants and facilitators, Couric was hardly the only one who didn’t pick up on his transgressions. She produces real-time texts as evidence of their deteriorating rapport; eventually, she realized that their relationship was so broken by the scandal that they’d never speak again.

One can’t help but feel that Couric got out of the highest-profile part of the business in the nick of time. When she interviewed Ann Coulter in 2002, she found her “hate-based non-logic hard to respond to.” How would Couric manage the moment we live in now, with near-constant attacks on the mainstream media?

She doesn’t need to worry much about how she fits into the media landscape today. She and her husband are wealthy enough to have created Katie Couric Media, a company where she can practice journalism exactly how she wants, without having to rely on “some network bozo” to decide if she’s still got it.

Couric has not written a capital-J journalism tome, self-righteously outlining the highest ideals of her profession. Rather, she pulls back the curtain on her life and times in the business, with much to celebrate and apologize for.

Most of the tabloid attention on the memoir focuses on the criticisms Couric doles out to fellow famous media and political types. Her cohort may be offended by the anecdotes she has shared. But as she blows up the charade of her chipper morning-show self, she is getting the thing that matters most in media, regardless of age or experience: attention.

Going There

By Katie Couric

Little, Brown. 510 pp. $30