Yet, she confesses that Decker and other young starlets have got her thinking about getting older.
"You know what makes me feel old? When I see girls who are 20-something, or the new crop of actresses, and think, 'Aren't we kind of the same age?' You lose perspective," the 43-year-old said in the March issue of InStyle.
Then again, there's nothing like Hollywood to remind an actress of her age - like "being offered the part of a woman with a 17-year-old child," Aniston said. "It's like, 'I'm not old enough to have a 17-year-old!' Then you realize, well, yeah, you are."
But, she added, "I don't feel my age. I feel young every day."
Perhaps, her boyfriend Justin Theroux has something to do with that.
Aniston told InStyle that she's in a "joyful" and "peaceful" place in her life, and is wiser when it comes to love.
"Having experienced everything you don't want in a partner over time, it starts to narrow down to what you actually do want," she said. "As I get older I realize what qualities are important in love and what suits me. And what I won't settle for."
The actress also insisted once and for all that there is no bad blood between her, Brad Pitt and Angelina Jolie.
"There are so many [misconceptions]. I would say the triangle with my ex-husband - and that there's a feud there … It's a story headline that won't go away," Aniston told the magazine. "It's a … story that has nothing to do with reality."
The public's fascination with the actress's love life hasn't waned since her 2005 split from Brad Pitt; the tabloids have followed her every move as she bounced from relationship to relationship, while her ex settled down with Jolie and started their globe-trotting family.
Now Aniston seems ready to settle down with Theroux, a 39-year-old actor and screenwriter she met on the set of "Wanderlust," their new flick about a couple who moves to a commune.
The two have been dating since last May and are reportedly ready to buy a new home in Los Angeles's Bel-Air neighborhood, for an estimated $22 million, according to the Wall Street Journal. Paparazzi have spotted the couple criss-crossing from coast to coast - house hunting, shopping, and on several occasions, sporting matching outfits.