Meryl Streep Before She Was Meryl Streep

Feb. 26, 2010 — -- An actress can be known for her emotional intelligence, her physical wit, her sensuality or her humor. She can be known for her versatility or her playfulness, or for her ability to deliver a dramatic monologue in pouring rain and not look silly.

Meryl Streep is known for being perfect.

As a Polish Nazi refugee: perfect. As a neglected corporate wife: perfect. As a single mom on a Greek island, dancing and belting out ABBA tunes: perfect. For her perfect portrayal of Julia Child in this year's "Julie & Julia," Streep is an Oscar nominee for a record 16th time.

But what about the early years, before Meryl Streep was Meryl Streep?

Watch "Before They Were Famous," on a special edition of "20/20" Tuesday, March 2 at 10 p.m. ET

ABC News recently sat down with two figures from Streep's past -- her best friend in high school and her graduate school drama coach -- to talk about the star's teenage days and her early stage career.

So what was she like back then? Pretty much perfect, it turns out.

"She was very outgoing. She had a great personality. Extremely funny," said Susan Castrilli, a friend of Streep's from Bernards High School in Bernardsville, N.J. "She was -- you know, I think the Meryl that you see now is the Meryl that was 14 years old. I don't think she's really changed all that much."

Michael Posnick directed Streep at the Yale School of Drama.

"It was just clear that there was something massive, monumental, really Himalayan about her work," Posnick said, "and about her gifts. And they're marvelous gifts. ... It's totally magic. There's a part of it that can't be explained. It's just an ability to become a character that represents a huge part [of] humanity. She's terribly human, wonderfully human."

New Jersey Days

Castrilli met Streep one summer day on the way to the pool. The Streep family had just moved to town.

"I used to cut through the woods to go to the community pool, and there was this blonde sitting on the porch there," said Castrilli. "It was a screened-in porch, and as I'm passing she looked up from a book she was reading. She said, 'Hello.' I said, 'Hello.' And she wound up at the high school."

Streep's given name is Mary Louise -- but she already was known as Meryl.

"Her mother gave it to her, actually," said Castrilli. "Her mother gave her the name Meryl because it was Mary Louise -- Mary L. She was named after her grandmother."

'She Looked Great Doing It'

At high school, Streep was everywhere, Castrilli said. In addition to acting, she sang in the choir and was class treasurer and homecoming queen.

"She had a great personality that everybody liked," said her friend. "I mean, you know, she was just somebody that you wanted to be around because every minute was something different. She didn't like to linger on things for too long. She always liked to explore and see different things."

Streep was a cheerleader when Castrilli was captain of the squad.

"She was beautiful," Castrilli said. "Everybody loved to sit there and watch her with her short skirt jumping around. It was great. She's very athletic, and you had to be athletic to be a cheerleader. ... And she was not only athletic, but she looked great doing it."

Streep had her share of high school boyfriends, Castrilli said -- including one who would go on to make a name of his own.

"Funny story, she went out with J. Geils from the J. Geils Band," said Castrilli. "He was a senior at Bernards High School when we were freshmen. And it wasn't a serious dating relationship, but she hung around with him, and he -- seniors were allowed to drive to school. And he drove her. ... So you know, and it was kind of like a -- senior dating a freshman, whoa. It was almost scandalous, you know? ... I honestly think she could have her pick of whoever she really wanted to have a relationship with."

High School Acting

But above and beyond all her other pursuits, Streep was the perennial lead actor in everything from "The Music Man" to "Li'l Abner" to "Oklahoma."

"As a sophomore, she starred in the first musical that Bernards High produced," said Castrilli. "She starred in that as a sophomore. Now, usually they saved the starring roles for seniors. She was Marian the Librarian in our sophomore year. She was Daisy Mae in 'Li'l Abner' in our junior year. And she was Laurie in 'Oklahoma!' in our senior year -- all three starring roles.

"Once she was in 'Music Man,' you didn't, you had no idea that anybody would get a role while she was there," she said. "And it's not because the teachers favored her; she was just the best. ... And when you're the best, you should be the best."

"Driving. I'm pretty sure that she kind of smashed up the driver's ed car, I heard," said Castrilli. "I know she smashed up the car once when I was with her. I had my license. She only had her permit, but her father gave us his beautiful, big car because we were gonna go driving around town like big shots, you know. And she wanted to practice.

"So he let me be responsible. The one with the license. So we're sitting there, and she's starting to go down a road, and she said, 'No, I don't want to go. I want to go back home and get something.' I said, 'All right.' So she just turned and hit the gas and BAM -- into a telephone pole.

"We got out, and there was this dent in the trunk and the bumper. And it was just awful. There was no way to hide it. ... When we went home, it was not a happy household."

Graduate School Days

Michael Posnick taught at the Yale School of Drama in the mid-1970s, when Streep enrolled after graduating from Vassar College. He still remembers the first time he noticed her.

"The first time I saw her work was in an acting exercise in one of the studios at the drama school," said Posnick. "And it was, I'd say, about an hour-long, wordless exercise, where the actors were working on a Chekhov play called 'Three Sisters.' And the actors just kind of moved about the stage, maybe interacted some. But I'm thinking it was an opportunity to kind of discover their characters in a particular space.

Click here to see video of Meryl at Vassar

"There is this woman, on the sofa, face down, reading a book. And it was Meryl Streep.

"There were some very talented people on that stage with her, or in the exercise with her," he said. "But I have to say, I couldn't keep my eyes off of her. There was something about the depth, about the size, the capacity, the intensity of what she was doing. And I would look around, and finally my eyes would come back to this woman. She was just reading, reading a book on the sofa. But, the size of her intensity was huge."

In 1975, Posnick directed Streep in a production of "Happy End." She was cast in a small part, "one of the Salvation Army lassies," he said. Then one night, the actress in the leading role fell ill.

"Meryl was not the understudy," said Posnick. "But she stepped in, after an afternoon's rehearsal, and played the play. And I remember standing in the back of the theater in awe that she had absorbed the entire production, absorbed the part. And they're singing songs in there. It's a musical ... where you have to really be present, and she had the whole thing down. And not only that, I watched her invent the character in a different way than she had seen it.

"And of course, in that situation, everybody's very awake and alert. And everybody's feeling her, energy-wise and, life-wise. And so she just swoons to triumph."

Posnick said that he still is amazed today watching Streep on the big screen.

"I sit in amazement. I just sit in amazement," he said, "at her capacities, and her abilities, and her gifts and her generosity. I think of all the things that she gives as an actress, she gives fully, all the time. She's always there, always present, great intellect and great heart as well."

'I Don't Know If She Had a Choice'

Success is never foretold, but for those who knew her when she was young, Meryl Streep seemed always to be on a path to greatness. Posnick said her future as an actress was clear.

"Oh, crystal clear. I think -- I don't know if she had a choice," Posnick said. "That was the direction. There was no equivocation. Just as onstage and in film, there's no equivocation. Everything's crystal clear. And that was her then, as well, from that moment on the sofa, it was crystal clear, there was no mistake, there was no ambiguity. She knew what she was doing, and she knew what she wanted to do. So, I really think in terms of her career, I think she was aimed like an arrow and was destined to do this."

Castrilli said she will be watching the Oscars next week and rooting for Streep. It has been a few years since the two last talked, she said. But she doesn't doubt that her old friend is the same as ever: Meryl Streep has always been Meryl Streep.

"I mean when you're starting out, you know, you make a few mistakes," said Castrilli. "But, you know, the term 'perfect' comes up a lot with Meryl whenever anybody talks about her. It's like, 'Oh, she's perfect. She's got the perfect hair. She's got the perfect cheekbones. She's got the perfect talent. She's just perfect.'

"And you know, it's not so much that she's perfect. It's that she's real. She's like a real honest-to-goodness person that you trust. ... She has everything going for her, and I think it's because of that honest-to-goodness realness that she seems so perfect. "Obviously nobody is perfect," she said, "except maybe Meryl."

Watch "Before They Were Famous," on a special edition of "20/20" Tuesday, March 2 at 10 p.m. ET