Sadie Jean never expected any of this. Her breakout hit "WYD Now?" boasts over 40 million streams on Spotify, a natural outgrowth of its organic viral beginnings on TikTok with views in the millions. The far reach has shown that the song's aching piano sound and message of heartbreak have resonated deeply.

She didn't expect this from a lovelorn track she penned with her friends and fellow students Grace Enger and David Alexander on a creative weekend getaway. But that doesn't mean she didn't work hard to make it happen.

"That was the craziest experience of my life," she tells us in the premiere episode of MTV News Presents: Rising. As the 19-year-old tells it, ending up here feels wild, even if she's been preparing for it for essentially her entire life.

At 3, she would enlist her sister to jot down song ideas down for her because, well, she hadn't learned how to write yet. That means she boasts a personal songwriting portfolio that dates back to elementary school and spans, as she said, "drama on the playground."

The drama of "WYD Now?," though, stems from a much more mature experience.

"I was so sad about my ex-boyfriend," she says with a massive knowing smile. "A few days before we left [to go work on music], I sent a Snapchat to Grace of me, like, sobbing. And I was like, I think this weekend will be a great writing trip."

She posted the song to TikTok the day after it was completed. From there, she says, "it went kind of crazy." She kept tabs on the play count, and by the following week, not only had she gone viral, but other creators's videos using her song were also going viral, and in certain cases, even more viral.

To maintain the momentum, Jean started an open-verse challenge on TikTok, inviting other folks to lend contributions to her song. One of them was Lil Yachty. "I died," she says of seeing the rapper's take on her song. "I just didn't expect that at all. Everything surprised me."

But nothing surprised her more than when that TikTok fame translated to actual success once "WYD Now?" saw its proper release on streaming platforms. She found this out, naturally, during a notoriously stressful and perilous time for students: finals week. While sitting in class, she made sure to keep an eye on the play counts as they ratcheted up and send messages to co-writer Enger, who was down the hall taking a different course.

"We would be texting, like, oh my god, it's about to hit 500,000! In the first day!" she explains. "And then we would run out, and I would wave by her window when she's in class, and we were jumping up and down. And then it was on the iTunes charts. It was so wild. I still don't feel like I've processed any of it."

One thing she has done is perform the song a bunch of times — including an intimate, piano-only rendition for us in our studio.

Check out the full interview with Sadie Jean in the first episode of MTV News Presents: Rising, where she also performs the song in full and answers fan questions, in the video above.