The now 30-year-old artist—winner of 10 Grammys, seller of millions of albums—isn't one to go into too much detail when it comes to her parents' personal lives, but the subtle details in the song—"Holy orange bottles, each night I pray to you," "You like the nicer nurses, you make the best of a bad deal"—paint a vivid picture.

"Everyone loves their mom, everyone's got an important mom," Swift recently told Variety. "But for me, she's really the guiding force. Almost every decision I make, I talk to her about it first. So obviously it was a really big deal to ever speak about her illness."

Sadly, she also revealed that Andrea was diagnosed with a brain tumor—which doctors found while she was undergoing treatment again for breast cancer, and which comes with a whole different set of challenges. Her mom's precarious health is a big part of why Swift decided to limit her touring in the U.S. this year to four stadium dates before she heads to Europe in the summer for the festival circuit.

"I feel like I haven't done festivals, really, since early in my career—they're fun and bring people together in a really cool way," Swift said. "But I also wanted to be able to work as much as I can handle right now, with everything that's going on at home. And I wanted to figure out a way that I could do both those things."

Ultimately, though, the reason is that she doesn't want to be away from her mom for too long. "I mean, we don't know what is going to happen," Swift told Variety. "We don't know what treatment we're going to choose. It just was the decision to make at the time, for right now, for what's going on."

(Originally published Aug. 13, 2019, at 11:15 a.m. PT)