The Sex Tape star graces the magazine's August issue, on newsstands July 8, and proves she's happier – and hotter – than ever at 41.
"I love it," Diaz says of being in her 40s. "So much s– just falls away. Fear, mostly. It's the best age. That's when a woman knows how to work things, or she doesn’t care about that anymore. You just stop being afraid. You don't worry about what men think. You just don't worry that time registers anything awful."
Though Diaz has been linked to Good Charlotte guitarist Benji Madden (a pal told PEOPLE she’s "really happy" with the rocker), the actress doesn’t see kids in her future.
"It's so much more work to have children," she tells Esquire. "To have lives besides your own that you are responsible for – I didn't take that on. ... A baby – that's all day, every day for 18 years. Not having a baby might really make things easier, but that doesn't make it an easy decision. I like protecting people, but I was never drawn to being a mother.
Diaz has also learned not to care about baring it all: She strips down in Sex Tape, marking the first time she's been completely nude on screen.
"It's a first for me. But Jason [Segel, her costar] gets naked, too. It's just part of the role. So I did it. I mean, you see everything."