Mary Elizabeth Mastrantonio thinks Americans should maybe just get a grip.

The 43-year-old actress, whom love transforms from strumpet to saint nightly in "Man of La Mancha" at the National Theater, doesn't mean to sound unsympathetic to her fellow countrymen traumatized by terrorism, anthrax, war talk and the sniper. Her very profession, after all, involves feeling and interpreting somebody's pain.

But she says we appear to have lost sight of the fact that love, hope and fantasy are the best vaccination for the human psyche against unthinkable horror. You still have to muck through the swamps of life, in other words, but you navigate better with your eyes on the stars.

"In fact, that's what 'Man of La Mancha' is all about," she says, brown eyes widening under her corona of corkscrew curls. "My favorite line in the play is the one that speaks of Don Quixote 'laying aside the melancholy burden of sanity.' They think he's just a crazy old man. But he's found a way to survive amid the inhumanities of life. And in the process he transforms Aldonza."

Aldonza is the tavern wench Mastrantonio plays in this high-tech revival of one of Broadway's most durable musicals from the 1960s -- the Dale Wasserman-Mitch Leigh-Joe Darion production that taught us "to dream the impossible dream." Some dinner theater somewhere in America has been engaging audiences with that show-stopper almost nightly since "Man of La Mancha" left Broadway in 1971 after five Tony Awards and 2,328 performances.

The current revival, at the National through Nov. 10, is scheduled to open on Broadway Dec. 5.

"Man of La Mancha" made "The Impossible Dream" the promising anthem of the 1960s. It became the unofficial campaign song of Sen. Eugene McCarthy's stop-the-war-in-Vietnam presidential campaign until the anti-war movement turned bitter with assassinations and riots that seemed to leave all dreams, possible or not, in smoke and dust.

Hope and idealism have had a hard time in the years since. Ten years ago when the last "La Mancha" hit the National, then-Washington Post theater critic Lloyd Rose derided the musical as "monstrous . . . kitsch" about "the courage not to face reality." Some would call that the most profound misreading of the play possible, but it did say something about the times.

Are we any less cynical about Don Quixote's message today? "Well, I don't think the play is about not dealing with reality," Mastrantonio says. "What it addresses is the power of the imagination to see beyond reality to something better and embark on a quest for that."

Those who can't understand that distinction, she says, "have never suffered very much" because understanding the true power of the imagination "only comes from great suffering . . . great hardship . . . from having it keep you alive and sane in some place like Auschwitz. But that was the [Spanish Inquisition] world in which Cervantes lived, and that is the world in which Aldonza lives: violent and unpredictable, with death and pain all around."

Mastrantonio says that most of the people who see this play in Washington and New York "will not have suffered very much" no matter how shaken they may feel by the current climate of public affairs. Nor, she says, will most of the actors who will play in it, including herself. "That's why a truer picture of man through art comes now out of places like Hungary and Czechoslovakia and Germany. We say, 'Oh, he suffered, now there must be closure.' But that's not reality in the rest of the world: It's hard today, it's going to be hard tomorrow. In this country, people whine if they even get their braces off. Americans don't experience real life. What they experience is television."

However rarefied her profession as a stage and screen actress, Mastrantonio remains exceedingly mindful of hardships. Her grandfather emigrated alone from Naples to Chicago and sent money back to Italy for 10 years until he could afford to send for his wife and son.

If her father was better off as a foundry worker, she says, "I always had a very practical streak. Whenever we would go to a play, I was always looking in the back of the Playbill wondering where such-and-such an actor is now. I've always believed if you want to starve for your art, your art is very willing to let you."

In fact, she's never had to. Growing up in Oak Park, Ill., she was the fifth of six sisters. When one of the older ones won a musical part in a high school production of "Plain and Fancy," 6-year-old Mary Elizabeth took a close look at the footlights afterward and decided: "I can do this."

Grade-school dramatic efforts were honed amid the "truly remarkable" resources of Oak Park River Forest High School, a 4,500-student facility with three theaters, great teachers and innumerable productions and concerts. Teachers told her she had an operatic soprano and for two years she took classes at the University of Illinois at Urbana-Champaign. But she discovered she "had no passion for opera."

An Italian with no passion for opera?

"I know, but I just didn't identify with it. Maybe it was the language."

Instead, put off by the "terminal seriousness" of the drama students and the "too much attitude" of operatic hopefuls in the voice department, she gravitated toward the more relaxed singers in campus musical comedies and two summers in Nashville singing show tunes at Opryland.

"I guess I was just your basic-package ingenue," she says with a smile. "Brown eyes, perky, Midwestern and able to roll out of bed in the morning and hit a high C. So I kind of fell into things. But the truth is I was never very focused. I was always kind of swept along by friends of mine who were far more ambitious."

One post-Opryland day while cast in a dinner-theater chorus of "Camelot" outside Chicago, she was dragged by her friends to a cattle-call audition downtown, where producers were casting for several musical road companies, including "Evita" and "Sweeney Todd."

Asked to sing something, she delivered a song from "West Side Story" -- she'd played Maria in college. Musical director Paul Gemignani heard her, pulled her aside and said: "Somebody you've never heard of is going to call and offer to fly you to New York. Just do what he says and get on the plane."

Off she flew to understudy the part of Maria in the 1980 revival of "West Side Story." She was 22. Clearly no suffering for art so far.

"It actually was weirder than that," she says. "One of the girls I'd shared a dressing room with in Chicago said, 'My college roommate is an agent in New York' and gave me a name and a phone number. So even though I'm not good about making calls, I did. And she was very sweet and came to hear me one of the days I actually sang, and after the performance in came a rose and a card that said, 'Call me tomorrow.' So now I had an agent."

She worked steadily -- from Public Theater musicals like "The Human Comedy" to a Shakespeare in the Park "Twelfth Night," in which her co-stars were Jeff Goldblum and Michelle Pfeiffer.

"Film just . . . came. One day, two years after 'West Side Story,' I was in 'Amadeus' and I got a call from my agent, who said I should go to a meeting with this movie casting director. I read a few scenes for him and he said I should come back in the afternoon and meet 'Brian.' This was on the East Side. All I could think of was, 'What can I do on the East Side for two hours?' There wasn't even a place to eat lunch."

That must have been suffering for her art. Because from that came her chance to get slapped around by Al Pacino in a men's room and filled with bullets in the Brian De Palma remake of "Scarface."

"I never had a screen test. I hadn't even been to enough auditions to be nervous. They just said read a scene and I thought, 'That I can do.' And that was it.

It certainly was. In her next film, "The Hustler" sequel "The Color of Money," her performance opposite Paul Newman netted her a nomination for Best Supporting Actress. Since then, the films have rolled on, including "The January Man," "Fools of Fortune," "Class Action," "My Life So Far" and "Limbo." More recently, she was on-screen as swordfishing captain Linda Greenlaw in "The Perfect Storm." But there continues to be a lot of time onstage, too.

"I got away from musical roles pretty quick in New York because . . . stage directors have this thing where they think a part in a musical isn't really acting. And it was sort of true for me. I really didn't know how to act when I came to New York. For the first 10 years, it was all I could do just to keep up with the opportunities placed in front of me. I didn't have the preparation. I do now, but I didn't then . . .

"And the thing about the stage, particularly a part like Aldonza, is you never do it the same every night. If you did you'd get bored. So every night you try something a little different. You take the role in one direction and see how it goes, and then in another. And if you have a good cast, you play off each other and that sparks the performance. Film is less intimate. But then you finish and get your money and go home."

As the mother of two sons (she's married to Irish director Pat O'Connor, who directed her in "January Man"), "I tend to be very practical about working hours."

For the past 10 years, she has lived in London, where the same sort of serendipity led to her casting as Aldonza. She was at a fundraiser chatting with director Jonathan Kent when she asked what he was up to. He said he was off to the States with a new production of "Man of La Mancha," starring Brian Stokes Mitchell and Audra McDonald.

"I told him God bless and good luck and said I'd always wanted to do that musical in a small theater: good part, great music, one act and you're home by 10 o'clock. Like I say, I think of the practical side of family life.

"He laughed and went off, and a few weeks later I'm at my son's school when my cell phone rings and it's Jonathan. Audra McDonald has had some TV pilot picked up and gone off to make a television series and would I like Aldonza. He'd never even heard me sing. He just took somebody's word.

"So we had some family discussions -- this was May and they wanted me in New York in August -- and there was a lot of rejigging with schools and things for the boys, but that's how this business works."

Meanwhile, she's wrestling -- quite literally -- with the role of Aldonza, who gets knocked around quite a bit in this very physical production. She is not exactly a whore with a heart of gold, at least not in the beginning. Not until Quixote infects her with impossible dreams.

Mastrantonio's films roles include boat captain Linda Greenlaw in "The Perfect Storm" and Moira in "My Life So Far" (with Colin Firth, below).Mastrantonio in "La Mancha." "I don't think the play is about not dealing with reality," she says. "What it addresses is the power of the imagination."Mary Elizabeth Mastrantonio portrays Aldonza in "Man of La Mancha" at the National Theater.