Sissy Spacek is on her second glass of white wine, trying to think of the funniest thing that ever happened to her. In her whole life.

"I know the funniest thang," she says, Texas twang thicker than bluebonnet blossom honey. "It was after I made 'Carrie.' I hadn't worked for two years. I went down to the unemployment office in L.A. They asked me why I wouldn't take any parts and I said I was waitin' for some GOOD parts so they said I couldn't collect unemployment because I hadn't worked in two years and therefore I didn't qualify as an actress."

The winner of the 1981 Oscar for Best Actress (as country-western singer Loretta Lynn in "Coal Miner's Daughter") bangs the table with her tiny fist and lets out a throaty laugh, strands of strawberry hair cascading from a loose Katharine Hepburn topknot, wide blue eyes flecked with gold twinkling mischievously. "Can you beleeeve that?"

Her Raggedy Ann face is pale and scrubbed clean, with a saddle of soft freckles over the perky, upturned nose -- an innocent face with a luminous, eerie quality, a face critic Rex Reed once described as "a crocodile fetus." A few tables away in the Charlottesville restaurant, two gray-haired women in floral print dresses sit by the rain-splattered window, staring at Spacek (pronounced space-sick).

"No wait," she says, excitedly. "The funniest thing was back in Quitman her home town one time when my father and I were doing a Charleston act. He played this record and I'd go out on stage, swingin' my beads. My brother would sit on a stool, pretendin' to play a banjo. Well, my dad had these long-playing records, and he was so proud of himself because he had figured out how to put a piece of tape on the record so the needle goes on the right spot, you know? Well, the people who used the record player before him left it on 45. So the record started going Deetadeetadeetadeedley real fast."

She jumps up, all 5-2 ("and a half"), arms waving, freckled knees stabbing the air, sounding like a Munchkin on speed.

"The curtain goes up and the record's going Deetadeetadeedeedly and I'm just standin' there and my dad's in the wings going, 'Dance Sissy! Dance!' "

She collapses into the chair, out of breath. The floral print dresses have stopped talking. It's so quiet, you can hear the top pop from a Budweiser at the bar next door. Finally, Spacek drops her chin into the palm of her hand, bony elbow propped up on the table. "Aaaw, that wasn't the funniest thing."

Suddenly, she's all nervous energy again. Small fingers drumming the table, hands slapping the thin freckled thighs conga-style. The waitress appears with two napkins. The floral dresses by the window would like her autograph. Spacek takes the waitress' ballpoint and signs her name in perfect Palmer script. "I'm goin' to the ladies' room. Jack, think of somethin' funny. "

Jack Fisk, noted set designer, film director and Spacek's husband of seven years, sighs. "What do you suppose people do with those napkins?" Fisk, who grew up in Alexandria and attended art school in Philadelphia, is 6-3, with a full beard, a wide gap between his two front teeth and a wry wit drier than the Texas Panhandle. He and Spacek have driven over to Charlottesville in their orange Volkswagen beetle from their 160-acre horse farm just north of the city. They will appear in Washington tonight at the American Film Institute for the premiere of "Raggedy Man," a haunting new film by Fisk (his directorial debut), starring Spacek in her first post-Oscar role.

"Okay guys, this IS the funniest thing that ever happened," says Spacek, returning to the table. "I'm in the ladies' room and this woman recognizes me and starts talking about how she's an actress and everything and I go in and I'm sittin' there and she's still talking, over the top, and it's really weird you know, because you have to be quiet and you can't . . ."

"Turn on the water," Jack deadpans.

She throws her hands up to her face and giggles. "It's WEIRD."

She's 31 going on 13. Unspoiled by stardom, undevoured by Hollywood. An irrepressible ham and a born mimic. A natural storyteller with a penchant for acting out all the parts, arms waving, eyes bulging. Street smart, sassy and girlishly sexy, fond of saying "Holy Moly" and "I'm gettin' goosebumps." The Real Thang.

"The two questions I get asked most often are, 'What was that stuff they poured on your head in 'Carrie'? And what was 'Three Women' about?' "

She picks out the black olives in her vegetarian salad and deposits them, one by one, on Fisk's plate. "The answers are, 'Karo syrup and food coloring' and 'I don't know.' "

The rain is still falling. Spacek, wearing one of Fisk's blue-checked shirts with the sleeves rolled up, rumpled khaki shorts and beige flat pumps, pockets all three clear blue mints wrapped in cellophane that come with the check. Time to head back to the farm. She pulls the hood of her tan jacket over her hair and walks to the Volkswagen.

"This may not be the funniest thing, but it was pretty funny. Jane Fonda comes up to me the other day and says, 'Hi Sissy.' Then she points to herself and says, 'Jane Fonda.' As if I didn't know JANE FONDA! I thought I'd daaaaiee."

She loves Jane Fonda. She loves Diane Keaton. She loves Meryl Streep. "I was in Sardi's one night, and Meryl Streep was sittin' there and she sees me and mouths the words, 'I LOVE YOU.' Well, I mouthed right back, 'I LOVE YEW TOO!' "

They drive to the camera store to pick up some pictures Spacek took of Fisk riding horses. She jumps back into the front seat.

"Now that was pretty funny. I pick out my wallet to pay for the pictures and all this white powder falls on the counter." To illustrate the point, she dumps the change purse upside down, spilling the rest of the white power (pulverized amino acid pills Spacek takes for cold sores) on the floor of the already cluttered car. "I just started laughing. The guy thought it was cocaine."

"Hooray for Hollywood," Fisk deadpans.

Next stop, the Gulf station. Jack gets out and pumps gas while Sissy stays inside, chatting about "Raggedy Man" and her upcoming record album. He comes back to the car with her credit card. "The guy inside said, 'Sissy Spacek? I like her. She's tough.' "

Fisk starts the car. "Which one, Jack?" she says. "I'll wave to him." The grease-covered gas station man is standing in the doorway, smiling and waving at Spacek. She grins like a small-town girl in her first beauty pageant, waving back.

"If they only knew how creepy you really are," she sighs. "But you know, I guess it's neat to fulfill a fantasy. People always think you're much grander than you really are." She looks at Jack, eyes twinkling. "Though I am pretty neat."

She leans over to the back seat, suddenly a little girl. "Ya'll got any more gum?"

They drive down the blacktop roads, past the lush green pastures, the hazy Blue Ridge Mountains and the small country store where Spacek buys grape bubblegum and where a local woman recognized her the other day and said, "I don't care what you do. I don't care how hard you work. You ain't NEVER gonna do nothing as good as 'Coal Miner's Daughter.' "

Windshield wipers slapping time, Spacek starts singing a song about a cow stuck on a railroad track. Fisk supplies the "Moos."

They pull into the long gravel driveway, lined with linden trees where Spacek goes jogging every morning. Past the 100-year-old farmhouse, the orange Volkswagen chugs along to the stables and stops near a fenced-in field where chestnut-colored quarterhorses and thoroughbreds graze in the soft rain with their spindly-legged foals. Fisk opens the gate. Spacek pulls off her tan pumps. "I'm not gettin' my shoes wet."

She walks barefoot through the wet grass, shivering in the damp air. They reach the horses and Spacek says in a soft voice, "Carry me, Jack." She jumps on his back and he holds her, piggyback style. Heidi, their buff-colored dog, barks and chases the galloping foals. Darkness descends on the fragrant field, warm with horse smells, as Fisk heads back, Spacek wrapped around his waist and neck. The silence is shattered by a faint voice, echoing through the mist.

"I know sumthen' real funny that happened once . . . " The Mellow Rose of Texas

She was born Mary Elizabeth Spacek on Christmas Day, 1949, in the piny woods of Quitman, Tex. (pop. 1,200), the youngest in a middle-class family of two boys, a father who worked as a county agricultural agent and a mother who typed legal documents down at the courthouse.

"We were country, but we weren't rural. We lived in town."

Spacek is stretched out on a chair in the tastefully furnished living room of the farmhouse, drinking a can of Tree Top apple juice. They bought the farm three years ago with a partner and use it as an infrequent East Coast retreat.

"I wasn't a beautiful kid. I was a little offbeat. I was always real independent, and I knew no fear. I was real ornery. I was a tomboy."

At the age of 4, she remembers going to the store with her parents to buy blue jeans for school. Her older brothers, who coined the name "Sissy," got jeans with zippers and a snap. She got jeans with elastic. "I remember crying. That was the first time I felt there was something very unfair, very unequal. I couldn't have something because I was a girl. It made me mad. So I wanted to be a boy."

She takes a swig of apple juice. "I thought, 'God, what a gyp, being a girl.' There are all these things you can't do because you're a girl."

She got into performing early, taking ballet lessons, tap dance lessons, organ lessons. When she was 13, she saved up her baby-sitting money ($14.95) and ordered a Silvertone guitar from the Sears & Roebuck catalog. "It took me six weeks to learn how to tune it," she says.

She never thought about becoming a star, she says, or even getting out of Quitman. "I just wanted to DO stuff. I'd play and sing and do the Charleston. It was easy for me. I always had an act."

She was a cheerleader for the Quitman Bulldogs, a majorette with the marching band (she still twirls a mean baton, as viewers of her guest stint on "Saturday Night Live" can confirm) and homecoming queen. "You have to understand," she says, laughing. "In my town, every girl was a majorette. We didn't have enough to fill up the line."

When she was 17, she was chosen runner-up in the Dogwood Fiesta, a local beauty and talent show. At the same time, her oldest brother, Robbie, came down with acute leukemia. To "get out from under" the family tragedy, Spacek went to New York, where she spent the summer with her cousin, actor Rip Torn, and his wife, actress Geraldine Page.

"Gerry would listen to me sing for hours. They really encouraged me. Rip introduced me to people in the music business."

One of the people Torn introduced her to was Bob LeMand, who now manages John Travolta. "He took one look at me and said, 'Honey, get rid of that accent or go back to Texas.' "

She did go back, but only to finish high school. Several months later, her brother died, which she says now "changed everything." Instead of going on to the University of Texas, as planned, she returned to New York after graduation to pursue a career in music. Rock music. She lugged a Martin 12-string around to studios, developed a crush on Duane Allman and finally cut a single (which she didn't write) under the name Rainbo. The song, "John, You've Gone Too Far This Time," chastised John Lennon and Yoko Ono for posing nude on the cover of "Two Virgins."

She also tried acting in commercials, and took the advice of a friend who suggested she enroll in the Lee Strasberg Theatrical Institute. "They'd cry and sing and I'd think, 'They're crazy. What's goin' on?' It was neat. We all went to this place afterwards and had coffee and that was neat, too." After six months, she quit.

It was easy for her, she says, to move into the fast lane because she was so young-looking and inexperienced. "I picked up a lot that way," she says. "I was an unthreatening force. When I first got to New York, people I admired the most would be talking about this film and that director and I thought, 'God, someday I want to be part of the conversation, just to join in. To stop being the little sister. To be taken seriously.' "

In 1970, she landed a small role in Andy Warhol's "Trash." The next year, she was tapped for a part as a young victim of white slavery in the emminently forgettable "Prime Cut," starring Lee Marvin and Gene Hackman.

She tried modeling, but got rejected too often. "I thought, someday I'll find people who will appreciate me. I was always too short or too young or too this or too that."

Shortly after that, Spacek moved to Los Angeles, where she appeared on "The Dating Game." "I picked an ex-marine motorcycle cop," she says."I wanted to make up my own questions, and they wouldn't let me. Like, 'If you were in my salad what would you be?' I'd have picked the guy that said, 'Tomata.' "

In 1973, Spacek met writer-director Terence Malick ("Days of Heaven"), who gave her the role of Holly, Martin Sheen's teen-age girlfriend in "Badlands," the saga based on Charles Starkweather's crime spree in the 1950s. The film was a major critical success, but a minor box-office one. "After I worked on 'Badlands' I felt like a filmmaker," says Spacek. "He Malick let me be part of the film. And also, I met my husband on that film. It was the right place at the right time."

She and Fisk share a home in the Topanga Canyon section of Los Angeles. She also owns a small lakefront cottage in Quitman. Financially, Fisk says, they are comfortable. "Let's just say we can now go into a restaurant and order whatever we want."

The doorbell rings. It's a Federal Express delivery man. He hems and haws and finally, through the screen door, asks for Spacek's autograph. Instead of a piece of paper, he pulls out a $20 bill. She signs it. "Save money that way," he drawls, grinning from ear to ear. Grown-Up Girl

She returns to the living room and puts a cassette tape of a country band on the recorder. "Everything I've ever done has been for acceptance and love. I got a lot of attention, but I always wanted MORE. I always used to dream about somebody coming up and saying, 'YOU. You are the one we need. Thank God you walked in here. You're exactly what we wanted!' I wanted to be the missing link, the one person who could save the day. When I was little, my dreams and fantasies were about a burglar coming to the house and I would wake up and save everybody in the family."

After "Badlands" came Robert Altman's "3 Women," which won her the New York Critics Award as best supporting actress. Then came "Carrie."

Spacek's performance won her the 1976 National Society of Film Critics award as best actress and her first Oscar nomination.

"It put me in a frenzy," she says now. "You're going along, doing what you do, nobody pays any attention to you, and all of a sudden everybody goes . . . "

She whips her head to one side and glares dramatically. "You get real self-conscious. You have to change your way of thinking." At the Academy Awards ceremony, she says, "I felt like an outsider. I didn't know anybody. I didn't feel like I was part of Hollywood."

The portrayal of the teen-age girl with telekinetic powers prompted a surge of weird ingenue roles, all of which she turned down. "I'd be ridin' my horse and some kids on bicycles would go by and scream, 'Ooooh, It's Carrie! Run!' "

She collapses into laughter. "After 'Carrie,' I didn't work for two years. I thought, 'How can I possibly top this?' "

She did. But not right away. The next film, "Heart Beat" (Spacek portrayed Carolyn Cassidy, widow of Jack Cassidy and close friend of Jack Kerouac), fizzled at the box office. But when Loretta Lynn's autobiography, "Coal Miner's Daughter," was being cast, Spacek's childhood dream came true. The country-western singer took one look at Spacek and said, "That's Loretta."

She says now that after the film wrapped, she had a hard time unbecoming Loretta. "What frightened me into cooling it completely was that I became horrified of the thought of doing a scene in some other film and having Loretta slip out. I used to tease Loretta though, and say, 'I get to be a lot of different people, but you have to STAY Loretta.' "

After "Coal Miner's Daughter," but before winning the Oscar, she filmed "Raggedy Man" in Texas with her husband. Fans of Spacek will be pleasantly surprised by her sensitive portrayal of Nita Longley, a divorced switchboard operator with two children trying to survive in a small Texas town. It's a grown-up role, one that Spacek cherishes because it is, she says, a portrait of her mother.

"We look quite a bit alike," she says. "She's a little taller than me, but then everyone is."

Last Christmas, Spacek says, her mother was the only one who could ease the self-generated pressure building up before the Academy Award. "She said, 'Honey, what difference does it make? People just want you to enjoy it and be yourself and be sincere and gracious. They don't expect you to be anything or do anything.' I thought, 'Yeah. I just have to be me.' "

Oscar night this year, she says, was a "blast." When they announced her name, "Well, I'll tell ya, my brother used to have an Austin-Healy and you'd be going 50 or 60 miles an hour and then you'd flip this little thing and it'd go into overdrive Hhhhhhrrrrrrooooooom."

Loretta was there, she says. So was her family. So were her friends.

"Goldie Hawn nominated last year for 'Private Benjamin' and I have offices next to each other and there was this one suite in the middle a hairdresser had that we both wanted. On the afternoon of the Oscars, she sent me this note. 'I'll make a deal with ya kid. Whoever wins gets the hairdresser suite.' When she walked in that night, I looked at her and said, 'It's a deal, Goldie.' "

Two days after the award, Spacek left for Mexico to film a new Costa-Gravas thriller, "Missing," costarring Jack Lemmon. The film, based on the true story of Charles Horman, an American missing in South America after a violent coup, opens in March.

Since winning the Oscar, life hasn't changed much for Spacek. "If I never do another thing, I'll be happy. Oh, sure I guess it's made me bankable. You don't change so much, but people listen to you. You're taken seriously."

She wants to work with Fisk, and the two have commissioned several screenplays for possible films. She's also planning to record an album of original songs for Atlantic Records. "I think her success came at a good time," says Fisk. "I think it would have been harder to handle if it had come before I was also established. She's very competitive, you know, but only with me."

She rises early most mornings, jogs, reads, listens to music and goes horseback riding with local friends. She says she doesn't want to be a boy anymore, but the other day she went into Charlottesville on a shopping spree and came back with two boy's shirts and a boy's tweed jacket. She pulls on a pair of rubber boots over her navy blue socks.

"You know," she says quietly, looking out over the rain-spattered pond, the horses, the ducks. "When I was a kid I used to play that game where you had three wishes. I always wanted to be beautiful and for everybody to love me and to have a million more wishes.

"I think I got 'em all."