After 17 years in a strict religious household outside Toronto, Avril Lavigne had enough pent-up angst to effectively launch a new pop-punk paradigm. “I wasn’t really allowed to really go anywhere or do anything,” says Lavigne. “I was definitely a good girl with strong morals, [but] my parents watched me like a fucking hawk.”

Despite her hyper-orthodox upbringing, Lavigne’s early smashes, from “Complicated” to “Sk8er Boi,” centered on high-school averageness—endorsing reckless use of eyeliner rather than actual lawlessness. Rivaling the scale of bubblegum opposites like Britney and Christina, Lavigne’s 2002 debut record Let Go would sell 20 million copies worldwide, thrusting her into adulthood and global fame simultaneously. “The first 10 years after leaving home, it was like, ‘woo!’ I went wild,” says Lavigne. She adds, “No sleep, Jack Daniels and beer. I would say that continued until the third album, when I was married,” referring to her first marriage at 21 to Sum 41 frontman Deryck Whibley.

But after a decade of manic quasi-maturity, Lavigne’s energy drink-chugging pace would slow to deathlike stillness. In 2014, during her second marriage to Nickelback’s Chad Kroeger, she came down with Lyme Disease. “I was like, oh my God, am I done? I couldn’t think about anything other than breathing and eating,” she says of her now-public battle with the disorder, the inspiration for her sixth album and its titular first single, “Head Above Water.”

While her stamina isn’t quite what it was, today Lavigne has regained her freedoms and is planning a fall tour. Nor has she lost all that early-aughts angst. (Asked if recent single “Dumb Blonde” represented a reversal of her anti-Britney persona, Lavigne says “No.”) But she is a true believer in the power of positive thinking. “I do the whole gratitude list thing,” she says. “I can’t do [it all] the way I used to, but I look at how far I’ve come and I just thank God.”