"Julia, that spirit was very like my mother's spirit," Streep told "Good Morning America" anchor Diane Sawyer. "Joie de vivre. She had it. And a great sense of fun and [an] infectious ability to bring people along in whatever adventure she cared to take charge of."
But, Streep said, her mother was most certainly "not a cook." Growing up, Streep didn't know that one could do more with a potato than bake it.
"I knew what a potato looked like -- had a brown skin and you threw it in the oven, and forgot about it for about an hour-and-a-half, or two," she said, laughing. "But I'd never seen a peeled white potato ... we got mashed potatoes out of the box. And I had gone up to a friend's house when I was about 10, and they were in there peeling what looked like white tennis balls. I said, 'What are you doing?' They said, 'We're gonna make mashed potatoes.' And I said, 'They come in a box. What are you doing?'"
Meryl Streep has been nominated for 15 Academy Awards in her career, more than any other actor, for roles and films ranging from "Out of Africa" to "The Devil Wears Prada."
"Julie & Julia" centers on a young woman's attempt to cook all of Julia Child's dishes from "The Art of French Cooking" in one year, and blog about it.
But the film isn't just about the connection between Streep's Julia and co-star Amy Adams' Julie. It also focuses on the relationship between Child and her husband, played by Stanley Tucci. In one scene he calls her "the butter to my bread and the breath to my life."
"I think that the surprising thing for audiences has been that two people that look like your grandparents could be, you know, having sex and being in love," Streep said. "And see the best in each other and support each other's wild ambitions."
The audience also sees how their relationship endures over time.
"I think everything morphs," Streep said. "Like, what is it? The seven-year itch. Every seven years, you know, another person emerges, and you gotta buckle your seatbelt. And I don't know. I think that it is all about change."
Long and lasting marriages aren't static entities, she continued.
"I think it evolves and changes, and certainly their marriage went through really, really hard things, when Paul got so ill for so long. I think that when you're young and getting married, you don't know what you're signing up for. But you're signing up for a big job."
Streep is herself part of a long and lasting marriage, with husband Donald Gummer. For her 60th birthday Gummer gave her a toaster, among many other "wonderful things."
"He gave me a toaster because he likes toast," she laughed. "Keeping the marriage alive, right? The toaster was good."
The mother of four is about to become an empty-nester.
"My youngest is going to college in the fall," she said. "So much of your life focused on all of these kids. And [my husband] said to me, 'You know, 30 years now, we've had to be, somebody has to be home in September,' you know? And all the time. And we've never made any plans to go anywhere or do anything for 30 years, basically -- without considering that. And now we can. It's sort of great."
Asked if she feels there's a whole new adventure out there for her, Streep said, "I don't know."