THINK," SAYS BERNARDO Bertolucci in a sober Italian accent, "I think that I am a repressed person. I think I can express my energy, my libido, my aggression, only in my work. We are all Dr. Jekyll and Mr. Hyde. We know our ghosts. And we don't tell anybody, not even our partners, about our ghosts. We live with our ghosts. We keep the ghosts inside in our life. It's just in the moment that Jekyll becomes Mr. Hyde that I can put my ghosts on the screen. I think I have understood this through psychoanalysis."

Bernardo Bertolucci, once the enfant terrible film-maker of Italy, the creator of "Last Tango in Paris," the arrogant young artist who took sexuality to new limits of creativity, the passionate Italian who creates controversy with every new venture . . . Bernardo Bertolucci has done it again. This time he has done it with "1900."

The controversy has taken its toll. The former wunderkind is now 36 years old, but he looks 40. The lines around his eyes, his forehead, weren't even visible when he first came to New York five years ago for opening of "Last Tango." He is quieter, easier, more comfortable with himself, somewhat fatigued, but certainly more mature. He is nicer, sexier. He is, well, grown up.

"The controversy is finished now," he says quietly. Then he shrugs and smiles, just a little mischievously. "I'm looking for the next one now."

Bertolucci believes, though he doesn't want to, in destiny.

He sighs. "La forza del destino," he says. "If you're violent or provocative, you don't know it. You are what you are even if it's not your intention. You are what you are.

"This film, it's (explosive) in a way," he says with no little glee. "It's outrageous. I use any kind of material in an outrageous way. I use opera and drama, I use two boys born on the same day when Verdi is dying. It's outrageous."

He loves the idea. It pleases him. "I wasn't afraid," he says, "to go deeply. I enjoy it."

He laughs.

"But you know," he says, "I am not completely screwed up."

But sometimes, he says, when he is not working on a film, when he does not have an idea - as for the past year and half, during the political negotiations of "1900," when he really did get sick - he is filled with anxiety, with despair.

"I was like a spinach," he says now that he can laugh about it. "Like a vegetable. My life passed by me like water from a stream passes over a rock. It was nothing. It was terrible.I was sick."

What he does, when he is in such despair, is simple. "Pills," he smiles. "I take pills." And he reaches in his pocket and pulls out a tiny plastic container of pills. "Here," he says, "read the label. Ansiola. That's what I take. My pills." And he says. "I have lots of symptoms when I have problems. I am a . . . how do say . . . a hypochondriac.

"I deal with anxiety," he says, "by trying to analyze what's going on, by trying to understand why I am feeling this way.

"1900," says Bertolucci, "was really a great effort. It was very tiring.

"My partner, Clare, she was my assistant director. She helped me a lot during the fight.It's too bad she can't be here with me now. But she was very strong. She was, well, in Italy we say, "If my grandmother had wheels she would be a wheelbarrow." Clare was that for me. She was my support.

"Because you know," he says, "when I make a film, all of me goes into it. Otherwise there is no other reason to feel alive, to live. It is also communication, being in touch with a lot of people. Don't you think it is probably a great need of affection. See my movie.Look my movie. Touch my movie. It's always indirect but the movie is the extension of me, the extension of my dreams. To me, dreams are very important. I use my dreams. I interpret them. It's hard work. It's discipline. You learn to do it through Saint Sigmund."

He leans forward, very solemn. "Do you know that you die if you don't dream? It's true . . .

"When you begin analysis," he says, "you think you will be cured. For me it has been eight years now. And the problem for me is not to be cured. It doesn't exist.

"The important thing is to find a harmony with yourself. Accept yourself as you are. I think I accept myself now. I couldn't before. I don't know how much I like myself but I accept myself. It's finished with these mixed feelings of a little bit of hate or love, the extremes. I live better now in the company of myself. It's strange. When i began in analysis I was afraid to lose something; I thought that to be analysed was to understand what used to be mysteries inside you. I thought it would make me give up my inspiration. But it was just a form to resist my neuroses that didn't want to be counseled by analysis."

He props his orange-stockinged feet up on the coffee table of his hotel suite and slowly lights a Winston as he reflects.

"But I don't," he says, "think I've lost anything. I think I've gained."

He still has a boyishness to him which is appealing, particularly when he is being serious. He is sincere, gentlemanly, polite, well-mannered. "Bien eleve" (well brought up) he offers with a grin. There is no question that he is intelligent though occasionally he will get carried away with his own philosophizing, his own political Marxist dialectic, his own attempts at profundity. And he has to be nudged into laughing at what otherwise could be considered pomposity.

At one point, after expounding on a philosophical point at length, he is questioned about a contradictory detail and his face falls, then he smiles. "What I tell you is paradoxical," he says.

"If you want to go into details then the whole theory, everything will fall apart."

What was, five years ago, an arrogance camouflaging insecurity, has been tranformed into a humility based on self-assuredness.

He is dressed, this morning, in a maroon silk shirt open and hanging out, a black sleeveless undershift, tan corduroy trousers and orange wool socks. No shoes. He is totally relaxed and confortable, and sprawls in a comfortable chair alternating between smoking Winstons and chewing gum.

He has just finished reading what he considers a very good review in Newsweek and is quite pleased with the fact that his film is called an "epic."

Now he sends down to the desk for Time, and when the bellman brings it up, he grabs the magazine and begins to read it aloud as he paces back and forth in his room. "Listen," he says excitedly, "listen to this.

". . . For years to come, those who love film will savor and analyze each exasperating moment.

"I like that," he says, plopping back down in his chair satisfied and pleased. "I like that. Exasperating," he repeats, savoring the word.

Bertolucci seems vaguely melancholy, his enthusiasm at the good reviews not as euphoric as one might suppose. He explains it as being a combination of things.He says he is enormously relieved that the film has been finally released, and that that has released him. And he says that at the New York premiere last Saturday night, "I felt I could finally get separated from the movie.

"The movie," he says, "was a sort of monument to contradiction. I'm not afraid to say it. But it was also a communication with the audiences. My earlier movies I didn't care about the audiences. I was much more arrogant before."

He says that though the movie was a celebration of contradictions, there was a change "from contradiction to dialectic . . ." And yet, he contradicts himself again by saying. "The audience doesn't care about dialectic, about those things. They care about emotion. And in the end it's the emotion that, God bless, cancels all this stuff."

And yet, he says, "I feel abandoned as if the movie has abandoned me. Not me the movie. I've been eith it for four years. That's long enough to be a marriage. And all that time it was so up and down, up and down."

Part of what made him feel that abandon, that loss, was that. "In '1900' I faced my whole life in a way. I faced my adolescence, which is really very near me inside. To go straight ahead we must have a look back behind us. That's why, when I finished '1900' I got sick. I was sick for months, emotionally sick. Nobody knew. Because to me my adolescene used to be the lost paradise and I created again my adolescene. my childhood in '1900.' And I created a copy of the lost paradise. And I lost it for the second time. Now I have really lost it. To let go of the movie was letting go of my childhood."

Five years ago, when Bernardo Bertolucci came to America as the celebrated young director, he had just broken off a four-year relationship with a young woman he then referred to as his "wife," though they were not married.

Then he scorned marriage as bourgeois and had given no thought at all to fatherhood. All that is changed, mainly, he says, because of his experience with this latest movie.

Now, he says, "I want children. I think to have children you must accept the idea that you are an adult. I think now I can manage it. It's not a decision I made. It's something that happened. It happened because of '1900.'"

Now, he says, he has been living with the same woman for four years. Clare Peploe, an attractive, but not movie-star beautiful, English woman of 36 who has been his assistant director on "1900."

Now, he says, he will probably marry her. "I have just considered it recently," he says. "But only for practical things. She is English and it would make it easier for her to live in Italy."

He is still, however, not totally sold on the joys of matrimony.

"We come from a world where marriage was destroyed by the generation before us. We are shocked by the examples of marrage that we have before us. The idea of marriage was made empty, and our generation, I think, is in the middle. But now the younger ones are getting married.For our generation we took love seriously. We refused to make it a social part. The new generation is using marriage as a life raft. They are so lost."

Sex and marriage are themes that dominate most of Bertolucci's movies, and they are subjects he thinks about a lot.

"I think it is a personal thing with me," he says, "but I think that sexuality is maybe the most important think in a person's life. To me it is so obvious because if you think about how you became a person, if you go back with your memory, see your behavior is completely determined, not so much by your sexual life, but by your sexual formation as a child. In one way I think it is fundamentally important and in another way I think it is completely natural I think that is why you don't feel embarrassed at the sex in my movies. And maybe why you do feel embarrassed in some American movies."

For Bertolucci, sexuality is naturally wrapped up in his maleness and the sex in his films is often personal.

"The male," he says softly, almost shyly, "we are very vulnerable with this object we have. If you think how fragile we are, we have to prove to everybody and ourselves our virility. And of course with all that has happened with the liberation of women, men feel much more vulnerable."

He was bitterly criticized by feminists for showing only female nude scenes in "Last Tango" and not male nude scenes. So in "1900" he has the two male leads totally nude in bed together with a prostitute. With close-ups.

He insists, however, that he feels differently than most men on this subject. "No," he demurs. "I feel better first of all because I agree completely with this movement politically. Oh," he says, stopping himself in disgust. "That is a stupid thing to even have to say. Of course I agree with it.

"I think because of the movement we can have better relationships.

"I don't feel especially Italian," he says "not in the sense of macho. I'm not a macho." He pauses, looks slightly guilty and amends. "No more," he says with a grin.

Bertolucci is just now beginning to plan his first movie star almost two years of being, as he says, "a spinach a vegetable." He says his next movie will be called "La Luna" (the noon) and "it is too delicate a subject to tell about it because it might break it, but it explores a relationship. It is more like "Tango" than '1900'"

In a strange way he is both looking forward to making it and dreading making it.

"Because when I make a movie I am of the attitude that it is as if I was making my last movie. That's why my movies are always so full of things. Maybe as a director we are not immortal in this society of consumerism. We live as it if we are immortal but our values are so false. You lose the idea that you could die tomorrow. When I shot 'Tango' I couldn't even think of '1900.' I was totally consumed. I am that way with everything. I am that way with women, too. I am completely involved with things. I'm very romantic. When I maek a shot I must think it is the only one possible, the only shot I will ever make. But when I say I think it is my last movie, I do not mean necessarily that I will die. I mean onlt that I may never be able to do one again."

He quickly reaches down and grabs his crotch and rolls his eyes heavenward.

"A superstitious Italian," he says laughing, "would touch his b - against bad luck."