Smith is also currently the subject of her own one-woman show, called "More," which chronicles her lonely childhood, her runaway ambition and 25 years of battling bulimia. Her eating disorder began before she had even turned 13 and, despite frequent roles in film and on television, was exacerbated by failing her goal of winning an Oscar by the age of 30. Her bingeing and purging wasn't even assuaged when she won an Emmy for her work on "The Simpsons" in 1991; convinced it wasn't an authentic kudos, she kept the statuette in her closet for nearly a decade. Her one-woman show--funny and touching if a tad long and a bit self-indulgent--had a brief off-Broadway run last spring and is currently playing in Los Angeles through March 6. Smith, 40, recently spoke with NEWSWEEK's Brian Braiker about her tortured quest for "More." Excerpts:

NEWSWEEK: Is it difficult to do a stage production when you're known for your voice?

Yeardley Smith: Since my beginnings are in theater and I worked so much on camera before I got "The Simpsons" I never actually felt like a voice. So for me it didn't count. It had nothing to do with the show itself. It had everything to do with the fact that I had laid myself a very specific plan, which included a couple Academy awards by the time I was 30 and anything that deviated from that plan just didn't count. So I spent a lot of time focusing on what was not yet done and missed all of the things that had already been accomplished and that, I think, was the tragedy of the situation.

No, you didn't win that Oscar before 30 but you are on one of the all-time great television shows.

Oh absolutely. First of all, I was always enormously proud to be on "The Simpsons." The writing is so fine. To be on a show for this long that you can actually hold your head up about is a miracle. And I love Lisa Simpson. She's truly one of my favorite characters of all time. I think even if I didn't play her myself she would be one of my favorites. She's so fabulously layered and complex. But if I didn't have this razor's edge ambition, I might not have gotten as far as I did as quickly as I did considering I didn't have any inside show business connections. I really was this kid from nowhere.

You've played an 8-year-old for 16 years. How has that affected your own development?

I think I got to work out a lot of my own childhood social angst with Lisa Simpson. I did drama from a very early age and I got a lot of attention from it right away. It set me apart. I was also quite shy. I know that Lisa Simpson struggles with trying to fit in with her peers as well and it's quite sweet really and ever so tragic and so real. But my other theory is that Lisa Simpson's plight as an 8-year-old reflects the plight of the writers on our show. They were all incredibly brilliant and by many of their own admissions sort of socially nerdy and not necessarily the hippest kids that ever walked the planet. They get to pour all of that into sweet Lisa Simpson.

And you won an Emmy for it. How did that affect your ambition, your bulimia?

When I won the Emmy, they presented it where they present hair and makeup and all the technical awards. They don't televise those awards. The reason that I kept my Emmy in my closet for nine years was the very next week I presented an award at the televised Emmys and as I walked out on the red carpet not one person asked me what it was like to win an Emmy the week before, so I deduced in my own little mind that it must not have counted for anything. It was really I think ultimately incredibly confusing. I would turn all of my anger and disappointment in on myself, which would be an instant unfailing trigger for my bulimia, which was already raging out of control.

As someone who was so obsessed with impossible fame and beauty standards, can you talk about what it's like to be a woman, who is no longer in her 20s, in Hollywood?

I had an epiphany. Last July I turned 40 and I remember in the months leading up to it I was really dreading it. Inside I felt like it was some sort of announcement that if you hadn't made it by 40, you'll never make it. Then my birthday actually came and it was so bizarre, it was as though the bricks had been lifted off my chest and I felt, "Well all right then, I am 40, I have arrived." There was this tremendous freedom that was so welcome and so unexpected. Now that I have been binge-purge free for two years, I find that while I still obsess about my weight, I obsess less about it. There comes a kind of acceptance when I look in the mirror now.

But by anyone's standards you're a raging success.

I know. [Laughs.] That's the peculiar and inexplicable disconnect that made me want to write my show. I thought, "What is the matter with you Yeardley? Why is it that your perception of yourself is so different from everybody else's?" I may not ever be out from under the feeling that I didn't do absolutely everything I could have done.

If at the end of your life, say 60 or 70 years from now, all you're known for is Lisa Simpson ...

[Laughs.] You know, that would be quite all right. She's a fantastic legacy and I have a complete understanding that she and the show itself are now so much a part of the fabric of our culture, in this day and age, that it would be foolish to think, or even try, to somehow shake it or make it less than what it is. For myself, for my own soul and my own satisfaction, I would hope it's just not the last thing I get to do. But if that is the epitaph then I can totally live and die with that.

How much longer will "The Simpsons" run?

I don't know. We're about to start recording season 17.

What about the movie?

If we do a movie, which we will do I gather, we won't start production on it until the show is over. Then it takes several years to develop, because they don't want to water down their writing pool while the series is still going strong. So I think maybe one more year after this. I don't know. Every time I say that it ends up being three or four more years.

Last year the whole cast of "The Simpsons" was in a very public battle over wages. Did you ever worry about coming across as unseemly or did you feel wholly justified?

What I learned from the first time we entered into an ugly battle, which was like season nine, we did come off as really being unseemly and we certainly felt wholly justified. Whatever the public gets wind of, they never get the entire story. If you're going to play hardball like that, you have to be able to say to yourself, "I can play and lose." You have to really be able to walk away from the job if that's what you mean.

Wow, it got that close?

Oh sure. You're taking on one of the biggest business entities in the world and they have a stake in not letting you forget that. Of course there is strength in unity, which we learned. You just have to let your worries of public opinion go.