“It was important for him to make a brave statement on his own.”

Billboard is celebrating the 2010s with essays on the 100 songs that we feel most define the decade that was -- the songs that both shaped and reflected the music and culture of the period -- with help telling their stories from some of the artists, behind-the-scenes collaborators and industry insiders involved.

Over the course of Tame Impala’s hypnotic, critically acclaimed 2015 album Currents, the protagonist stumbles through various symptoms of heartbreak -- despair, paranoia, helplessness, optimism -- in a way that suggests a personal metamorphosis.

Then, in the final track, he’s nearly back to square one.

“New Person, Same Old Mistakes,” the woozy, six-minute long kicker, cautions listeners to be skeptical of anyone’s well-intentioned ability to change -- including that of the narrator himself. “I know that it’s hard to digest/ a realization is as good as a guess,” bandleader Kevin Parker sings, another tough pill to swallow from an album that might as well be a medicine cabinet. During the chorus, his past and current selves battle it out to the tune of distorted drums and a grumbling bassline: After the pompous “feel like a brand new person” comes the lingering, ominous echo, “but you’ll make the same old mistakes.”

In a 2015 interview with Billboard, Parker said he turned 29 while writing Currents, and became fascinated by the Saturn return, an astrology term for the massive life transition people often experience around that age. "I've been doing a lot of reflecting on my life in the past and what's ahead of me,” he said. “I was halfway through ­making the album when I heard about it, and it gave what I was doing a lot more meaning; ­suddenly things made a lot more sense."

While “New Person” ends Currents on a doubtful note, the album itself was transformative for Parker’s career. The band’s garage rock-driven debut Innerspeaker in 2010, and more smoothed-out sophomore album Lonerism two years later, had morphed the famously obsessive and elusive Parker into an indie hero. But it wasn’t just critics who revered his psycho-rock virtuosity: He also scored an unavoidable alt hit and a number of commercial syncs with the foot-stomping anomaly “Elephant,” which charged to No. 8 on Billboard’s Alternative Songs thanks to its chugging riff and spot-on analogy for, well, an egotistical jerk.

But Parker has never been one to stand still, and so with his new album, he threw that all to the side for a totally fresh and different sound -- and a new challenge. In addition to writing, recording, performing and producing Currents (as he did for the first two albums), Parker also mixed the music and recorded all instruments by himself for the first time.

Rob Grant, the Poons Head Studio producer and engineer who has worked with Parker since his days in Mink Mussel Creek, served as an advisor. “I was promoting him to not be scared of taking risks,” Grant remembers of their sessions at Parker’s home studio in Australia. “It was important for him to make a brave statement on his own.”

“One of the beauties of Kev is the desire to push something different, and something new,” he adds. “As soon as you stay still, they can nail you to the cross. But if you keep the target moving, they fight pretty hard to nail you down.”

The result was more polished, pop-leaning and commercially upfront than its rough-edged predecessors, painting a sheen over every note without losing any of Tame Impala’s trademark psychedelia. Compared to the crunchy guitar riffs of Innerspeaker, or ever-so-slightly pop turn of Lonerism, Currents beckoned listeners with layers upon layers of glimmering synths, vocal echoes and radiating bass to wade into -- a producers’ masterpiece for the 2010s. Currents peaked at No. 4 on the Billboard 200, was nominated for a Grammy and earned Album of the Year at the ARIA Awards, among five total honors for Tame Impala.

And while “New Person” wasn’t a single -- the disco-tinged jam “Let It Happen” became the critical favorite, while the antsy, schizophrenic “The Less I Know The Better” was the streaming hit (and remains Tame Impala’s most popular song on Spotify) -- it captures everything Currents has to say about the impulse to change, the desire to live up to that ideal self, and the ways we delude ourselves into thinking we have.

The song found a somewhat unexpected (but logical) fan in Rihanna, who famously covered it smack in the middle of her most experimental album, 2016’s ANTI, retitling her version “Same ‘Ol Mistakes” but keeping everything else intact. Parker suggested in an interview with Billboard that SZA may have introduced Rihanna to the song, and it struck a chord with the pop superstar, who was herself experimenting with a brand new sound (and who had no doubt been disillusioned by the idea that someone can change in the past).

Parker gave the cover his blessing -- in fact, he said he imagined “a female R&B voice” singing it in the first place. “I guess it comes back to appreciating ideas being malleable and being able to imagine music in different worlds,” he added. It certainly wouldn’t be the first or last time Parker intersected with the worlds of hip-hop and pop -- by now, he has become a go-to collaborator for the likes of Lady Gaga, Mark Ronson, Travis Scott, Kanye West and other stars looking to inject some psych-rock cool into their projects.

The song’s anxious spirit also seems to mirror Parker’s tendency toward perfectionism with his work. Asked how he and Parker knew that Currents was done, Grant is at first silent -- there’s no way to truly know. What mattered, or at least helped, was that their efforts were recognized in the end.

“The fact that someone who is a perfectionist could be rewarded as such made me feel really good,” he says. “It’s not just being an idiot that never gets to sleep.”