Jennifer Aniston talked about her past and what she wishes she could tell her younger self in the upcoming September issue of Glamour magazine.

Aniston's We're the Millers co-star Jason Sudeikis interviewed her for the magazine and got her to open up about her thirties, when she was married to Brad Pitt.

When asked what advice she would give her 30-year-old self, she replied, "Go to therapy. Clean up all of the s---. Clean up all of the toxins and the noise. Understand who you are. Educate yourself on the self." The 44-year-old actress divorced Pitt when she was 36 after five years of marriage.

"You can undo a lot of things," she added. "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."

Aniston, who is now engaged to fellow actor Justin Theroux, said that once you love yourself, you can attract other people to you.

She said that she would tell her 20-year-old self "not to fret so much. I did OK in my twenties." As for her teenage self, she advised, "Don't try so hard. Pay attention. Do your homework. Go to class."

In her new film We're the Millers, Aniston stars as a stripper who is enlisted to pretend to be Sudeikis' character's wife for a large-scale drug deal. Aniston told Access Hollywood in an interview published Monday about the diet she went on to play the role of stripper.

"Greens and vegetables and lean proteins and kale," she admitted. She added that once in a while she would have a "cheat day" and indulge in a kale chip.

Aniston can be seen in We're the Millers when it debuts in theaters nationwide on Aug. 6.

Watch this clip of Aniston in the film here:

Tags: Jennifer Aniston Brad Pitt we're the millers