The song serves as the opening track from the singer's recently released album, Plastic Hearts

Miley Cyrus is speaking candidly about her new music.

While appearing virtually on a recent episode of The Howard Stern Show, the 28-year-old singer opened up about her recently released album, Plastic Hearts, and shared more information behind the LP's opening track, "WTF Do I Know."

Detailing to Howard Stern that the song is about her ex-husband, Liam Hemsworth, the "Angels Like You" crooner said that when she crafts her music, it is sometimes based on what she happens to feel at that exact moment in time.

Comparing her songwriting to capturing a firefly in a jar, Cyrus said, "When I write a song, that's what I feel like. Cause I feel like I'm capturing something that is free and that I maybe only feel for a second. It doesn't have to be my identity, but it has to be a part of me somewhere."

"[And with] 'WTF Do I Know,' it’s not that it's how I feel every second of the day, it's how I felt for a moment," she added. "That works as some sort of protective armor and there's a sense of myself that does feel that way. A record is all of these mason jars filled with something that lights up, that you catch something that's kind of magical for a moment, but it doesn’t have to be you all the time."

Miley Cyrus, Liam Hemsworth

The song, which features a pop-rock vibe, finds Cyrus singing about the uncertainty of life and is a clear nod to Hemsworth, 30, who she split from last year.

"You want an apology? Not from me / I had to leave you in your own misery / So tell me, baby, am I wrong that I moved on? / And I, and I don’t even miss you / Thought that it'd be you until I die / But I let go / What the f--- do I know?" Cyrus sings on the track.

During her chat with Stern, 66, Cyrus also noted that her "I don’t even miss you" lyric from the song was about her ex "in that minute," as she described.

"Sometimes you miss people more than others, and sometimes, things get easier," she explained. "Time kind of heals all, but that was at a time where I felt really strong. And then some days I don't."

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Elsewhere during her conversation on The Howard Stern Show, the Grammy-nominated singer also opened up about why her marriage to Hemsworth didn't work out.

Cyrus and Hemsworth tied the knot in December 2018, and Hemsworth filed for divorce months later in August 2019, citing irreconcilable differences. The divorce was finalized in January of this year.

Cyrus told Stern that still loves Hemsworth "very much" and "always will," but "there was too much conflict." She added, "I don't get off on drama or fighting."

"I don't know if we ever really thought we were actually going to get married," she said, recalling how losing their Malibu home two years ago in a wildfire impacted their relationship: "Me being an intense person and not wanting to sit with it and not wanting to go, you know, 'What could be purposeful about this?'"

She added: "I just clung to what I had left of that house, which was me and him."