But a decade ago she was -- and she remembers.

"Ten years ago, work was everything," said Pfeiffer, 43. "It defined everything for me.

"It's still really important. I've always been a worker -- I love working. But my family is obviously my priority."

That's a lesson her character, Rita Harrison, needs to learn as she helps a mentally challenged man fight to regain custody of his 7-year-old daughter.

Sean Penn plays the dad, Sam, with Dakota Fanning as daughter Lucy. After a year-end run in Los Angeles to qualify for the 2001 Oscars, I Am Sam opens nationwide Friday.

I Am Sam has drawn a strange mix of raves for its acting, story and music, and withering pans from critics who despise its emotionalism. All seem to agree it's a four-hankie cry-fest.

But carping critics miss the point, says writer-director Jessie Nelson.

"I'd say, `Come to L.A. Goal and do your research,' " she said of the center that inspired and informed her story.

Much of that story stems from the people at L.A. Goal, a center with work and art programs for the mentally challenged.

Penn, Pfeiffer, Nelson and co-writer Kristine Johnson often went there before making the movie, and Nelson, who also produced, hired two men there to play Sam's friends.

"These people don't have the same governors on their emotions that we do," she said. "They express their emotions deeply and readily.

"But they also carry kindness and fun. They're incredibly joyous for people living in a world that doesn't really make room for them."

As Nelson sees it, sparking feelings "is my job. Critics call that manipulative, but what movie isn't?

"When you make a comedy, you're trying to get the audience to laugh, and you do your job well if they do. But if you tell a sad story and the audience cries, you're considered sentimental and manipulative."

Besides, I Am Sam can be funny and sunny, and it was enjoyable to make, Pfeiffer said.

Her Rita is a driven lawyer who wears Armani suits and only takes Sam's case pro bono when shamed by co-workers. Authorities have deemed Sam unfit to raise his 7-year-old. A workaholic, Rita is even less fit as a parent, but she learns from Sam how to connect with her own son.

Pfeiffer admits sharing some of Rita's insecurities and perfectionism. But she's the opposite when it comes to family. Each Saturday night she has a date with her husband, David E. Kelley, creator of TV's The Practice and Ally McBeal. She also carefully picks roles to maximize her time with son John, 8, and adopted daughter Claudia, 9.

A devoted -- but limited -- bowler, she calls Kelley and herself "the most boring couple in Hollywood" -- and seems proud of it.

Avoiding work in distant locations (I Am Sam was shot in Los Angeles), she's made just one film each year recently. In 2000 that was What Lies Beneath, the hit thriller with Harrison Ford. Due later this year is White Oleander, in which she plays an imprisoned woman trying to stay in touch with her daughter.

Nelson, who also wrote Pfeiffer's The Story of Us, says the actress was "in the back of my mind" when she created Rita's character.

"I'd also always wanted to put Michelle and Sean in a movie together," Nelson said. "I thought they'd have a strong collaboration -- and they did."

She and Pfeiffer both say they've met fast-talking, cell-phone-hugging women in Hollywood who focus on work at the expense of their personal lives.

"I've known this kind of woman from afar," said Pfeiffer, who learned her lines "really well" so she could talk rapidly as Rita. "It's somebody I've tried to steer clear of."

When asked if she was referring to women in the film business, Pfeiffer laughed. "I'm not going to say," she said. "But you don't have to be a lawyer in Century City to neglect your children. It's happening everywhere. People are forced into it when both parents have to work to make ends meet."

I Am Sam is drawing its share of upbeat reviews and turns some viewers into happily blubbering idiots.

But making the movie "was actually joyous and light," Pfeiffer said. "While we worked really hard, everyone was in great spirits."

That included Penn, 41, who "was like a sponge" at the center, Nelson said, "picking up a hand gesture, an intonation, a look in the eyes."

While folding T-shirts beside an autistic person, Penn caught flak for not doing the job precisely. So he learned -- then gave Sam that attention to detail.

Though she's a major star, with three Oscar nominations, Pfeiffer was intimidated at first by Penn.

"But he put me at ease right away," she said. "Sean works really hard to encourage you. I found that to be the same with Jack Nicholson (with whom she starred in Wolf and The Witches of Eastwick)."

Nelson echoed the thought.

"Sean teased me at the end, saying, `I've never behaved so well on any film in my life.' He was such a joy to work with and had tremendous chivalry with other actors."

She said her cast and crew "were enormously happy making this movie, which I think came from having people with disabilities on the set. You tend to drop your armor, forget you're making a movie for such a hard-hearted world and open your own heart a little bit."