President Ronald Reagan, fresh from the State of the Union speech that he called his return to prime-time television, reminisced yesterday about the good old days of movies -- days when actors kept their clothes on and Clark Gable had to get special permission to say: "Frankly, my dear, I don't give a damn."

If Gable had not put up a fight, Reagan recalled, Rhett Butler might have had to not give "a hoot," or perhaps "a fig."

In those days, movies didn't allow "damn" or "hell," the president said approvingly. "We told adult stories. You look at older pictures today, the adult can understand them, but you wouldn't be embarrassed if a child were with you seeing that picture."

As Reagan told the story, Gable argued that "hoots and figs wouldn't do." The president was speaking to a group from the Association of Independent Television Stations that had presented him with a glass statuette in the shape of a transmitting tower for "excellence in communication."

Gable told the filmmakers there was no other way you can have Rhett Butler say that line from the movie classic "Gone With the Wind" and not use that word, the president said -- careful not to use that word himself. "And finally the motion picture industry gave a special waiver and allowed him to use that one word."

"I'd like to see those days back, and I think all of you would be better off also because the entertainment you deliver is in people's living rooms where the family is gathered together. And I think that must be kept in mind," the president added.

The president said he wishes the television industry would work for less sex and bad language in motion pictures by "fighting back" against having to show such movies.

Reagan said he's not very happy about the movies today: "I liked it better when the actors kept their clothes on."

It's not only bad morals, Reagan continued, "I think it's lousy theater. The oldest rule of theater is that nothing you can do on the stage or screen is as good and effective as the audience's imagination. And we have taken that away from the audience. We just don't leave anything undone or unknown anymore. No one has to imagine, just sit and look and let it flow in."

Reagan praised the old system of voluntary censorship of motion pictures under Will Hays.

"I think motion pictures are what made single beds popular," he said to laughter, "because one of the rules that most people didn't realize was that you could not show two people, even married, in a bed together."

When Reagan played Grover Cleveland Alexander, the great baseball pitcher, he recalled, Doris Day played his wife.

In one scene they were meant to be in bed together, but the film showed Reagan getting out of bed and then, only when he was safely standing by the window, the camera showed Day in bed. "You never saw the two of us in bed together," he said.

Reagan was ebullient about his State of the Union speech and joked that it brought him back to prime time from the late, late shows on which his old movies are often seen.

"Somebody asked me once what it was like seeing myself on the late, late show, and I said it was like looking at the son I never knew I had," he said.

Reagan, who will be 71 on Feb. 6, told a questioner that "I've never felt better in my life."