In the April issue of Cosmopolitan, on stands March 10, the singer and actress opens up about her broken marriage to retired hockey player Mike Comrie, with whom she shares a son, Luca.
"Mike and I were very in love when we met," Duff, 27, told the magazine. "We both really wanted to get married. I'd been working since the age of 11 or 12, so making that choice at a young age seemed right for me. Maybe it wasn't, but we spent the majority of our time together really happy.
"It wasn't working well enough to stay together, but there was still a lot of love involved," she added. "It was just a slow set-in of us not being the match that we used to be. I'm lucky for the person he is and I am and how we decided to handle this."
On her view of marriage post-divorce, Duff said she definitely looks at things differently.
"I don't want to sound bitter because I'm definitely not, but I don't know if people are meant to be together forever. Things happen over a long relationship that you can't always fight. A marriage of 20 years, the accomplishment of that must feel really great, but there are also huge sacrifices. I just always want to fight for happiness."