"I want my kids to know when I'm pissed, when I'm happy and when I'm confounded," the actress, 42, and new face of Lancome, tells Elle in its September issue. "Your face tells a story and it shouldn't be a story about your drive to the doctor's office."
Roberts says she simply doesn't understand why some would go to all lengths to hold onto their youth.
"It's unfortunate that we live in such a panicked, dysmorphic society where women don't even give themselves a chance to see what they'll look like as older persons. I want to have some idea of what I'll look like before I start cleaning the slates," she says.
For now, the Eat Pray Love star is embracing her natural good looks, which landed her on PEOPLE's 2010 Most Beautiful issue cover for the fourth time. Her only fears? They're "more parental."
"You make these people and you love them and you want them around for a thousand years," she says about her three kids – 3-year-old Henry and 5-year-old twins Phinnaeus and Hazel – with cameraman Danny Moder. "And you want to be there for them for a thousand years."
The entire Roberts-Moder family, she reveals, goes to temple together to "chant and pray and celebrate. I'm definitely a practicing Hindu," says Roberts, who grew up with a Catholic mother and Baptist father.
And since in Hindu cosmology souls can be reincarnated in other bodies, where does she see herself in the next life? "Golly, I've been so spoiled with my friends and family in this life," she says. "Next time I want to be just something quiet and supporting."