In the movie, Bryan Cranston plays a man, Howard Wakefield, who has a nervous breakdown, and leaves his wife (Garner) to go live in his attic for several months.
"I think anyone can imagine just the desire to drop out of their own lives," Garner noted. "It's just to actually do it, to follow through and to live outside of your life [while] watching your own life for a year, [that] is pretty out there."
PHOTOS: Jennifer Garner Stuns in Sexy Lace Dress While Out in NYC As for whether she's ever thought of running away, the mother of three replied, "No I like my life, I'm not looking to go anywhere."
Garner -- who looked stunning at the premiere in a strapless black and gold Oscar de la Renta dress -- also praised Cranston for his performance in the film, calling him "the most fun.Read more at Entertainment Tonight