Ben Folds is in his mid-40s. But when it comes to his songwriting, that doesn’t mean what you’d think it means.

For his upcoming album The Sound of the Life of the Mind, the first in 13 years to be recorded with his reunited band the Ben Folds Five, Folds says the lyrics are “not so much all that shit about ‘I’m a family man’ or ‘I’ve been through divorce.'” No, says Folds, who is indeed a father and has indeed gone through a few divorces, “It’s more about that stripping of ego for me.” He explains: “Like, you go, ‘I don’t know everything.’ And you say, ‘My story isn’t what I thought my story was. I thought I was the guy that does this and this and this, and it turns out that’s all bullshit.'”

Anyone who has paid attention to Folds’ lyrical catalog could easily believe that the man already saw himself as a felony screw-up, repeat offender. After all, isn’t this the same piano-tinkler who made it big in the ’90s with a sinking-feeling song about his girlfriend getting an abortion? Isn’t he the same guy who sang about growing a mullet, considering joining the army, and having his dad tell him, “Son, you’re fuckin’ high”? It certainly seemed like he knew the physics of getting knocked down a peg when he sang on the 2005 track “Bastard,” “Pretty soon, you’ll be an old bastard too / You get smaller while the world gets big / The more you know, you know you don’t know shit / The whiz man’ll never fit you like the whiz kid did.”

But Folds learned a few new things about the heavy mantle of the whiz man when he started picking out tracks for The Best Imitation of Myself, a 2011 retrospective that included three discs of live performances and previously unreleased studio takes. As he pored over hundreds of hours of recordings that included early-career songs with bassist Robert Sledge and drummer Darren Jessee — the other two members of the Five, which only ever had three people — he cut himself a heaping slice of humble pie. “You would have never heard me in an interview in 1999 [the year before the breakup of the Five] say that I played with the best bass player in rock and roll, but I did. Why didn’t I say that? It’s true now, too,” Folds says. On the live recordings, Folds says, “I would hear myself talking at the shows and just go, ‘Who in the hell was this guy? This guy’s just a jackass.’ And then I would hear the band play together, and it would seem so evolved.”

The band reunited briefly in 2008, when Myspace commissioned them to do a one-off performance of their last album together, 1999’s The Unauthorized Biography of Reinhold Messner. In 2011, Folds called the band back together again to record three new, “appropriately retrospective” tracks for Best Imitation, but instead he found they were generating some “very new and very kind of future-ish ideas,” he says. Two of the new songs on the greatest-hits album were regret-laden piano ballads in classic Folds form, while a third, the Robert Sledge-penned “Tell Me What I Did,” featured sunny vocal harmonies, cascading synths, and a hard-rocking bass guitar line behind lyrics that sound like a grown-up take on the band’s once-youthful piss and vinegar.

After recording the songs for the retrospective, Folds finally decided it was time to reunite the band for good. “I’ve given up my ego enough to be able to submit myself to the band, and I think it’s been really rewarding,” Folds says. The new album is set for release on Sept. 18.

In the years since the Five last recorded together, Folds sowed his musical oats hither and yon. He recorded a doleful version of Dr. Dre’s gangsta rap classic “Bitches Ain’t Shit.” He served as a judge on NBC’s a capella show The Sing Off. And he collaborated with artists including William Shatner, Weird Al Yankovic, Regina Spektor, and — perhaps most fittingly — Nick Hornby, author of High Fidelity and About A Boy.

Folds, the rocker of suburbs and potty-mouthed Elton John of Generation X, teamed up with Hornby, the quippy English writer and king of the pop-culture-obsessed cynical romantics, to create the 2010 album Lonely Avenue. Hornby wrote the lyrics, Folds composed the music, and the result was a sometimes-hilarious hodgepodge of narrative-driven songs about a flinty author, a musician stuck with a hit song about an old flame, and Bristol Palin’s hapless ex-fiancée Levi Johnston.

Here were two artists who had made a living off of fearless self-honesty and near-total irreverence, united in song. An English major with some spare time could have a field day drawing a line from Hornby’s fake liberals “whose hearts bleed right through their Gap T-shirts” (in Hornby’s lesser-known novel How to Be Good) to Folds’ corporate-ladder-climbing “textbook hippie man,” who once wanted revolution but now finds himself becoming the institution (on Folds’ song “The Ascent of Stan”).

“What happens with his characters,” Folds says of Hornby, “is they have moments where they say shit you’re just not supposed to say, and it’s because they’re so honest … What that’s all about, I believe, is that people aren’t often very honest with themselves, and I think Nick and I try to find moments in our music and our songs and our books where we just say it. We say the things that you’re not allowed to say, and the reason I think that we do that is because both of us feel that it’s OK in a song or a book.

“Most people write, especially pop artists — we try to write from perspectives of strength, because that sells the brand. You know, like I love Led Zeppelin, but you know that the perspective is always going to be that of strength, because you’re buying into the myth. And that myth is very valuable, because it gives people something to shoot for. It’s what we call perfection, and we know we’re not going to achieve it. But then sometimes it’s time for the nerd to come along and say, ‘I’m actually not that strong. I actually don’t believe that I’m that good, and I actually don’t believe that all of my intentions are that pure. Actually, sometimes I’m a fucking asshole.’ And everyone is, and you relate to that.” Whatever and ever amen.