It wasn't just any society that filled the bright hall of the National Academy of Sciences last night to honor Lady Bird Johnson and watch a film of her life. It was the Great Society, dressed to conquer and complete with the Johnson daughters, much of the Johnson cabinet, Texas politicians and a Supreme Court justice.

"I was scared every minute," said Lady Bird moments after the film. "But I'm glad I did it. It's been a fantastically wonderful life, most all of which is because of Lyndon. And I thank you all for being our friends."

For a few in the large crowd, already teary-eyed, that did it. Out came the handkerchiefs.

"Oh gosh, Lynda and I reached over and held hands during some of it," said Luci Johnson. "I could hardly see the screen through all the water."

Everyone came to see a film of Lady Bird made for the LBJ library, but as the film is short (30 minutes), they spent most of the evening cheerfully congratulating one another on how well they've gone the distance.

"Oh I'm so lucky," beamed the former first lady as she stood with five former cabinet secretaries just before the 600 guests trooped into the theater for the show. "Imagine looking around here tonight and seeing so many of you!"

The secretaries in question -- Robert McNamara (Defense), Dean Rusk (State), C. R. Smith (Commerce), Alan Boyd (Transportation) and Willard Wirtz (Labor) -- nodded and grinned, and in general looked pleased as party punch.

"Do you think the new folks are having as much fun as we did?" said Wirtz, with a nod toward the White House. "I don't," he continued. "Poor them. They lost their sense of humor somewhere along the way. I'm going to write a book about it. I'll call it 'Wit's End.'"

Wirtz wasn't the only one making comparisons. Joseph Califano, a Johnson aide and a secretary of HEW before the agency changed its initials, rushed in to see the film, rushed out to congratulate Lady Bird on what everyone agreed was as Oscar-winning performance, and then paused near the buffet line. "What came through in that film, through all the flowers, and the children, was her compassion. And the compassion of all those programs. And you can say what you want about Reagan, but you can't say that."

The theater itself looked like a mini-legislature. Seated row by row were House Majority Leader Jim Wright (D-Tex.), Reps. John Brademas (D-Ill.), Claude Pepper (D-Fla.) and Jake Pickle (D-Tex.), Sen. Lloyd Bentsen (D-Tex.) and former senator Frank Church. Nearby was Supreme Court Justice Thurgood Mashall, a Johnson nominee, who declared the evening "old home week." Also spotted were Motion Picture Association of America President Jack Valenti, former CIA director Richard Helms, consumer advocate Esther Peterson, former assistant secretary of education Liz Carpenter, former social secretary Bess Abel and National Gallery Director J. Carter Brown. Whispering into his ear was Beryl Bentsen, wife of the Texas senator. She was talking up an art show.

Three Johnson granddaughters sat behind Lady Bird, Lynda Robb and Luci Johnson, who wore a white lace dress and looked, according to her niece, Kathy Robb, "just like Scarlet O'Hara." The granddaughters wore identical black velvet dresses, and as Califano went off in search of McNamara, and Helms, moments later, from a different part of the room, declared his intention to do the same, the granddaughters could be seen skipping and sliding on the slate floor. "Nini gave us these dresses," said one of them, using their nickname for Lady Bird. "Aren't they pretty? They're Christian Dior."

For Valenti, it was the second time he'd seen the film in one day. "I suppose," he said at an afternoon screening at the MPAA, "that if I were writing a book about this day, I'd call it 'A Remembrance of Things Past.'" He spotted Carpenter, who was Lady Bird's staff director.

"Ah, someone else from the old days," said Valenti.

"The old days? Old days?" said Carpenter.

"Why yes," said Valenti mildly. "The days of power."

"The First Lady, A Portrait of Lady Bird Johnson," was written and directed by Charles Guggenheim for the LBJ Library in Austin, Tex.Underwritten by MCA chairman Lew Wasserman, it was made last year at a budget of about $200,000 as a companion to the film on Lyndon Johnson already at the library.

Only 30 minutes long, the film is as interesting for its omissions as for what it includes. There is no mention of Vietnam, though there are long segments on the work the first Lady did on civil rights and the poverty programs of the Great Society, including the long, sometimes acrimonious whistle-stop tour she made through the South in 1964. There is colorful footage documenting her many beautification and conservation projects. There is scant mention of her daughters, Lynda and Luci, though there are brief shots of them and the Johnson grandchildren.

Veteran campaigner or no, Lady Bird made a reluctant movie star.

"I just keep pinching myself -- to make sure it's really happening," she said. "The film is made with a good deal of poetry, and . . . and I'm so glad it's over!"

She was asked about the fate of the Democratic Party, and whether she plans to campaign for her son-in-law, Virginia Lt. Gov. Charles Robb. "I'm most interested in the Democratic Party in Virginia," she said, and added that during Robb's campaign she "plans on being a very good baby sitter."

And as for the GOP's budgetcutting fervor, she said only, "I hope they'll take care of the flowers."