With only a single piano as accompaniment, Kelly Clarkson turned a teary performance of "Piece By Piece" on last week's American Idol into a full-blown hit, notching tens of millions of views via Facebook and YouTube and catapulting the song to No. 1 on iTunes (the Idol version's now available for download, too).

And while the singer's thrilled it's caught on, she told Ryan Seacrest on On Air this morning (February 29) that it's sort of a bummer so many people can relate to its sentiment.

"Piece By Piece," the third single off of Clarkson's 2015 album, chronicles her father's abandonment, and her subsequent trust issues with men.

"No one was more shocked [than I] that people liked it, because I was crying so bad...it's awesome, but it's kind of sad that people relate to this song," she said. "I was afraid to watch it, because I was like 'Oh, jeez, I don't know if I got anything out, if I was on key.''"

Clarkson said the emotion behind the song, which she wrote after a conversation with her sister, didn't occur to her until she was pregnant with her first child.

"I don't think I understood the gravity of it until being pregnant with River, my first little one," she said. "I was like, 'I cannot imagine not seeing this kid to his or her full potential and just seeing what she's going to do, what she's going to be like. Why wouldn't you want to be a part of her life?'"

On the upswing, the song ends with Kelly describing what it was like to finally find love, and someone capable of rebuilding her trust in men. This more universal feeling, she said, is what connected her to fans across her 2015 tour.

"I used to be such a Downer Debbie, when people were like 'Oh, you just have to find the right one,' and I'd be like 'Shut up, this doesn't exist, this fairy tale — good luck," she noted. "It was kind of nice on this whole live tour to get to talk about it before singing 'Piece by Piece,' because there's a lot of other girls and guys like me that have stories that are like me: 'Although you weren't shown this, it doesn't mean that it doesn't exist.'"

Listen to the full interview here for more, including a story about the time Kelly's father showed up to Idol, and share your thoughts on Kelly's final Idol performance.

Look back at 10 defining American Idol Season 1 moments: