Transcript for Charlize Theron opens up about 'Tully' live on 'GMA'
You never know what will happen on the subway. Another super talented guest. You know her from "Mad maximum" from "Monster" taking on the myth of the supermom in "Tully." Please welcome Charlize Theron. How are you? Hi. Good to see you. How are you? Good, good. Oh, right here? Wow. Okay. Is this the seat? Sure. I think I just switched the seat but that's okay. You can do that. Oh, no. It's impossible to ruin this movie from what I read. Great reviews. On and on and on and it's funny. It's real. You just seem like any role you take on, Charlize, that you just embrace it and it was -- this one as well. Well, I feel like I am the luckiest person on the face of the Earth. I have the best job, you know, and I think -- I know how lucky I am to have that. It's a luxury, right? Right. And I don't take that for granted. I absolutely love my job. You can tell in this role. Wait till you see her -- you even brought your mom to one of the premieres. Well, I can't get rid of her. You said she taught you patience. She did. Yeah. She is such a wonderful -- she's the greatest teacher that I have ever had and she from the first moment I became a mom, used to say this thing to me and it's so profound, she would just always say tomorrow is a new day. And it was just such a good feeling of line, oh, there is light at the end of the tunnel. When you have days where you're feeling like this is never going to stop. I'm the only person going through this. Nobody else is experiencing this. Why am I the only one and she would just giggle. We had that with colic for the first three months with Ellie. Never thought it would end. Thank god. I wasn't alone. See, we don't know this stuff because we don't talk about it or share how messy it is to raise kids or how hard it is. It is a great thing but it's Harvard and difficult and messy and that's okay. "The Washington post" called this your most fearless performance yet. Is that the way it felt to you. I think mothers are pretty fearless so -- I have the outmotor respect for moms and we don't give moms enough credit. And, you know, a lot of people are making a big deal because they gained all this weight for the film and how brave that is and I'm like, do you know that moms do this every day and nobody calls them brave. So this -- I really wanted this to do justice to mothers out there. Has there ever been a role or scene you were afraid to do? Every one over time, yes. There's this little voice inside of me that always says, they're going to find out that you're lying. Like they're going to find out that you're terrible. And that you have no talent and you can't do this, yeah and I think that little bit of insecurity is the thing that makes you work harder and you can't get complacent when you're in that space and that's a good thing as an actor. I don't ever -- I don't think I ever want to feel I got this. I don't think that would be a good space to work from creatively. Let's let everyone be the judge. We'll show some. Are you okay? Yeah. I make milk. So a lot of moms will watch this film and go, thank you, finally somebody showing what it's really like. You alluded to the fact of having to gain weight and some people would think that, as he a hard job or that must be a lot of fun to do but it really took a toll on you emotionally. It did, yeah. I dealt with depression for the first time in my life and I think a lot of it had to do with the amount of processed foods I was eating and amount of sugar and I just -- I was working with a set of twins on the set and a 5-year-old and an 8-year-old and I had a 1-year-old and a 4-year-old in the trailer and I literal just went from changing diapers on set to changer diapers in my trailer. It was just nonstop. I herniated a disc in my lower back. Had for injuries than in "Mad max" or "Atomic blonde." It's hard being a mom. The 30s come around the corner like a garbage truck at 5:00 A.M. Now you're in your 40s. What do you like about it? What's something different you experienced in your 40s. I felt so rushed in my 20s and running out of time constantly and it made me not stop and appreciate the moments that were happening to me and, I guess, that's part of being a 20-year-old. That's what makes your 20s your 20s. There's something that happened for me in my 40s where everything just slowed down to the right speed and I have perspective and there's like a little thing that happened to me that was just like I can say no and not be judged for that. I don't have to please everybody. I don't have to show up for everybody. I can make an adult decision and not be judged for that. That's a confidence that I never had in my 20s. You know what's a beauty when you find out "No" is a complete sentence. You don't have to say anything else. I think women struggle with that more than men. We do. So if I could go backo my 20s, I would definitely I would say that. That's -- that's going to stick with me now. You know what you say yes to, her philanthropic work and the causes you work for. Everything you have going on. Er woo he ahappy you can't say yes to coming here talking T us. We appreciate it, Charlize. The movie is "Tully." It's in theaters today. Make sure you check it out. Can't say anything better about it. Coming up more "Deals & steals" from Nashville.
This transcript has been automatically generated and may not be 100% accurate.