Since then, she's teased that she's not entirely ruling out a return to film: "Look, I'm never going to say never. I'm not a person who says never about anything, clearly," she said this past April.
But she hasn't really opened up in depth about why she left acting.
That is, until Gwyneth Paltrow got Diaz — "one of [her] best friends in the entire universe" — to talk more about it on a recent video for In goop Health: The Sessions.
According to Cameron, who is now busy with her own wine brand Avaline, the decision to move on from film was mostly due to her wanting to put that energy into her personal life.
"I just decided that I wanted different things out of my life," she told Gwyneth. "I had gone so hard for so long, working, making films, and it's such a grind. And I didn't make any space for my personal life."
So, she did a 180 and ended up prioritizing her family life. "I decided to stop making movies and really focus on my personal life, my personal relationships with my family, my friends," she explained. "And then Benji [Madden] and I met each other and we got married pretty much immediately because we both knew that we both had to do it."
"There's a lot of things that I had to iron out and a lot of relationships I had to repair. A lot of relationships I had to build that I was absent in," she added. "It's so intense to work at that level and be that public and put yourself out there. There's a lot of energy coming at you at all times when you're really visible as an actor and doing press and putting yourself out there."
Now that she's out of acting, Cameron says she feels "a peace in [her] soul because [she is] finally taking care of [herself]."
"I feel grounded and light," she told Gwyneth. "It's a strange thing to say. I know a lot of people won't understand it. I know you understand it."
But now that she's fully settled into a blissful personal life, maybe a potential return to acting really isn't out of the question. Like Cameron said, never say never!