The 34-year-old actress discussed the "trauma" of her five-month marriage and highly publicized divorce from Murray, her former One Tree Hill co-star, in the February issue of Cosmopolitan.
"In my 20s, when I was starting out my career as an actor, I wasn't looking for relationship, but one found me and became serious, even though I hadn't planned to settle down until my 30s," Bush recalled. "But when the person you're with asks you to marry him, you think: 'This must be happening because it's supposed to.'"
"But I refuse to let that one relationship define me, which is why I've done my best to avoid discussing it for 10 years," she said. "The reality is that, yes, it was a massive event in my life. And the trauma of it was amplified by how public it became, which was incredibly foreign and bizarre to a girl who'd just been another college kid 24 months before her life blew up."
Bush and Murray met on the set of One Tree Hill and married in April 2005 after two years of dating. The actress was denied an annulment after separating from Murray in September 2005, but was granted a divorce the next year.
"At the end of the day we're grownups, and I actually think what's interesting about it is that when people split in a way that's unpleasant, they usually just go on quite literally hating each other ... but when you have to work with somebody for another half a decade, you kind of have to deal with it," she previously said of the split on Watch What Happens Live.
"We were two stupid kids who had no business being in a relationship in the first place," the star admitted. "To all the other co-stars who've worked it out, more power to you."
Bush and Murray co-starred as Brooke Davis and Lucas Scott on One Tree Hill from 2003 to 2009. The actress has gone on to play Erin Lindsay on Chicago Fire, Chicago Med, and Chicago P.D.