That's the hard-won wisdom espoused by Jennifer Aniston in a candid conversation with guest interviewer and We're the Millers costar Jason Sudeikis in Glamour's September issue, on newsstands Aug. 6.
"You can undo a lot of things [as you get older]," the actress, 44, says. "If you're not happy, you can become happy. Happiness is a choice. That's the thing I really feel. Like with friends who refuse to get happy, who refuse to rise above the discomfort of where they're at."
At a certain point, Aniston says, you realize that "you actually deserve to have a family. And once you meet yourself, and truly love yourself, then you attract that. And look – I mean, the two of us have found these two, beautiful, loving, open people."
To which Sudeikis, 37, who is engaged to Olivia Wilde, replies: "We both went through the same thing. I mean, I would hear you talk about [guys you were dating], and I'd be like, 'Oh, f--k. I don't want to be like that to somebody else.' "
"Yeah. Yeah," says Aniston. "And look how far we've come! High five!"
On the subject of kids, Aniston says she and fiancé Justin Theroux are both naturally drawn to them.
Theroux, 41, "has extremely amazing paternal instincts," she says. "Because [growing up] he had to sort of become the parent. I think when you have to become the parent when you're a younger person, you learn those instincts."
Sudeikis points out that Aniston was very protective of Emma Roberts on the set of We're the Millers. But she says her maternal instincts are nothing new.
"I think I've done it all throughout my life," she says.