For Olivia Rodrigo, even hypothetical disappointment is a novel experience these days.

In September, her sophomore LP “Guts” became her second straight album to enter the Billboard 200 at No. 1 (after 2021’s quadruple-platinum “Sour”), while tickets sold out almost immediately for the arena tour she’ll set out on this year. Now, she’s up for six prizes at February’s Grammy Awards, including album of the year for “Guts” and record and song of the year for her miniature rock opera “Vampire.”

“I hate to hit you with the ‘it’s an honor just to be nominated,’ ” says the 20-year-old pop superstar named best new artist at the Grammys in 2022. “But it really, truly is.”

Though it’s oriented — as “Sour” is — around her emo-theater-kid vocals, “Guts” builds on Rodrigo’s debut in a few important ways. For starters, it’s more indebted to the ’90s punk and alternative rock she absorbed as a child, thanks to her parents: Listen for the identifiable traces of Smashing Pumpkins in the shimmering “Pretty Isn’t Pretty” and Bikini Kill in “All-American Bitch,” a sly yet furious critique of impossible feminine ideals with a title borrowed from Joan Didion.

Between albums, Rodrigo took guitar lessons — among the tunes she learned were Radiohead’s “My Iron Lung” and the Beatles’ “Something” — which is why she’s particularly gratified by a nod for the fuzzed-out “Ballad of a Homeschooled Girl” in the Grammys’ rock song category, where it’s up against cuts by boygenius, Foo Fighters, Queens of the Stone Age and none other than the Rolling Stones.

“I love that it’s for the song where I say, ‘Every guy I like is gay,’ ” Rodrigo says with a laugh during a recent interview not long after the premiere of the latest “Hunger Games” movie, for which she wrote a spectral chamber-folk song called “Can’t Catch Me Now.”

Rodrigo credits her producer, Dan Nigro, with pushing her to try out different styles and sonic approaches. “I sometimes think if it weren’t for him, I would have been writing sad piano ballads forever,” she says.

Yet it’s Rodrigo’s commitment to the character she’s playing — to the subtle variations in tone and attitude — that brings the music to life in a song like “Bad Idea Right?,” a jumpy new wave jam about reconnecting with a guy she knows she should avoid. And, yes, this former child actor does think of her performances on “Guts” as character work.

“That was an idea I was exploring a lot on this album — that the girl singing ‘Bad Idea Right?’ is totally different than the girl singing ‘Logical,’ ” she says. “This time, I wasn’t 17 years old, going through my first heartbreak, crying at the piano, and a song just flies out. I had to sharpen my songwriting skills and my singing skills. It felt like a different creative experience.”

“Guts” is also funnier than “Sour,” nowhere more so than in the rap-rock banger “Get Him Back!,” in which the singer roasts an ex without breaking a sweat: “He had an ego and a temper and a wandering eye/ He said he’s six-foot-two, and I’m like, ‘Dude, nice try.’ ”

None of this is to say that Rodrigo has forsworn the type of emotional melodrama that made her a star. In the pensive “Making the Bed,” she revisits the scene of her breakout breakup ballad “Drivers License,” imagining herself behind the wheel of a car as the brakes go out.

And one of the album’s most impressive songs is “Lacy,” a haunting and delicate acoustic number about a poisoned friendship that grew out of an assignment Rodrigo completed as part of a poetry course she took last year.

Like “Drivers License,” which came wrapped in internet gossip about Rodrigo’s alleged romance with a Disney castmate, “Lacy” has inspired widespread speculation regarding the identity of the song’s subject. (The most popular theories involve Taylor Swift and Gracie Abrams.) Rodrigo says she tries to ignore the chatter, though she has enjoyed the “more creative answers to who Lacy is — like it’s a past version of myself or the voice in my head telling me I’m not good enough.”

At any rate, she adds, “I just think it’s not classy to come out and say it’s about this person. I also think that would set a weird precedent where I’d have to clear the air with every song I write.”

Rodrigo’s tour launches Feb. 23 in Palm Springs, California — just a couple days after her 21st birthday. “I’m either not gonna do a party, or I’m gonna be really hung over for the first show,” she says, laughing. “We’ll see.”

Rodrigo, who joined Sheryl Crow to sing “If It Makes You Happy” at November’s Rock & Roll Hall of Fame induction ceremony, says planning the production “is really making me examine my identity as an artist, because I love going to a show that’s big and awesome, but I’m also not the type of girl who’s gonna break into a dance routine. That’s not me. So I’ve got to figure out a way to make it my own.”

On tour behind “Sour” in 2022, she says, “I didn’t know anything about performing. I was so green.” At the time, she said she had elected to play theaters (instead of the arenas she could easily have filled) because she didn’t want to “skip any steps” in her development as a live performer. Reminded of her rationale, she smiles. “If they’d put me in an arena back then, I would’ve been terrified,” she says. “I wouldn’t have known what to do.”

So what did the road teach her?

“That jumping around and singing — just the physical act of it — is the hardest thing.”

Going back to her old songs now in rehearsals has been another learning experience. “Some of them I don’t really love so much anymore,” she says. For instance? “Oh, I don’t want to tell you that. People get so sad because it’ll be their favorite song. But I just feel like I’ve grown out of some of them.”

She’s happy to report that “Drivers License” isn’t one of those, though she does hear her breakout smash differently today.

“I remember putting the song out, still super- heartbroken, and people would come up to me and say, ‘Wow, this takes me back to my first heartbreak,’ ” she says. “Now, I listen to it, and I totally get it. It actually does transport me back to when I thought I was never gonna love anyone else.

“I’m like, awww — that’s so cute.”