On Saturday, June 13, Garrison Keillor did his last radio show. He had broadcast "A Prairie Home Companion" for 13 years, during the last 10 of which I had become a devoted, if reluctant, fan. Keillor was not at first to my liking. His monologues were of an imaginary small town, the Minnesota Brigadoon of his boyhood, and I come from the big city, the biggest of them all. I made fun of him, but Saturday after Saturday I listened, and somewhere along the way I got hooked. I guess we all hail from Lake Wobegon.

But then Keillor quit. He announced his decision about two months before his last show. He was at the height of his popularity, with a huge audience for a public radio network few people ordinarily listen to. The year before, he had published a book, Lake Wobegon Days, and it was a best seller. His audience and his fame were growing. He could have stayed on the air a long time.

But he didn't. "I've simply come to the point where my material isn't as good as I want it to be," Keillor said in an interview. "It's time to pull away, listen to the way people talk. I need the discipline of reporting to get back my ear for dialogue." With that, he pulled up stakes for Denmark, the homeland of his new wife, Ulla, with whom, any listener could tell you, he is madly, almost boyishly, in love.

It's hard to come up with the names of other people who quit at the top of their form. "Doonesbury's" Garry Trudeau did it temporarily -- and then came back in brilliant form. Another is Greta Garbo. From 1926 to 1941, she appeared in many American films, some of them, like "Grand Hotel," "Anna Karenina" and, of course, "Ninotchka," classics. She made but one other and retired, saying (or not saying), "I vant to be alone." As a public person, she effectively died at age 36, leaving nothing but her film and a myth. Now nearly 82, she remains fixed in both film and memory as young.

Occasionally -- but only occasionally -- an athlete quits before he absolutely has to. Joe DiMaggio, whose pride was a match for his talent, did that. He retired in 1951, no longer in his prime but still playing ball better than some athletes at their best. Mostly, though, athletes wring their careers like towels, getting every drop before they are finally told there is nothing left. We are told they do this for money, and maybe because an athlete's career is brief, it's true. But there are other reasons as well. One of them is the desire to remain occupied, and there is nothing mysterious about that. But there is another reason, and it makes Keillor's decision all the more stunning.

Most public persons -- the actor, the athlete, the performer -- ultimately allow their audience to define them. You're good if your audience says you are. This tends to confuse quality with popularity, performance with celebrity. For some people, the latter -- fame -- becomes a version of Vince Lombardi's winning: not everything, but the only thing. To be mentioned in a gossip column because you were seen eating in a certain restaurant becomes the equivalent of a good review. The media take the pulse of the person, announce to him that he still lives. Obscurity means that the mirror of the media reflects nothing back.

The occasion of Keillor's retirement was widely and even disproportionately noted. For a radio, especially public radio, personality, he was incredibly famous, but his audience measured a meager 3 million -- a Nielsen-ette, by television standards. There are many in the media, of course, who simply wanted to salute a performer who frequently raced across the blurred border between talent and genius. But there were others, I think, who were stunned and, maybe, envious that a performer had retired in his prime. The novelist in all journalists, the writer in all anchormen, was paying attention. Here was a man who listened to his inner voice and heard it above the cacophony of books sold, ratings, contract demands, endorsements, recognition and, of course, applause.

Keillor says he's a shy person. Hardly. Shyness suggests feelings of inferiority, a lack of confidence. But it takes tremendous confidence to quit while on top. Most wait until others "retire" them -- either their audience or, in the case of the athlete, time. But Keillor rang his own curtain. "It's time to pull away . . ." We would still have listened. We would have praised and lauded even when -- even if -- the work was not as fresh, not as original, not as good as it once was. Eventually, maybe, we would have turned him off. Conceivably, he moved on before we could.

J.D. Salinger has not published a work in more than 20 years. But he continues to write. In a sense, he, too, quit while on top, but from Cornish, N.H., where he has lived for 34 years, we can imagine the sporadic sound of a typewriter -- the sputter of a brilliant writer now unsure of his work, now maybe out of gas. Somewhat the same thing happened to Henry Roth. He wrote Call It Sleep and then, blocked, little else. But he, too, did not really quit. He would write if he could.

Keillor stands almost alone. Week after week, year after year, his audience listened to him, but he did not listen to it alone. His raw material was memory, and his imagination turned it into a finished product. After 13 years of mining the little town that time forgot, Lake Wobegon, he could hear what his audience could not -- the sounds of inspiration fading. He quit, he said, to return to the life of a shy person. He will listen, he will think, and he will, because he was brave enough to quit, be brave enough to come back. ::