Sid Caesar has seen crazy Saturdays. And Sundays, and Mondays, and crazy every other days. The Saturdays we shared with him, on TV in the '50s. The other days were his alone.

It's a little sad now to see Sid Caesar schlepping his way from one TV talk show to another, plugging his new book, "Where Have I Been?" and telling the same stories of his rejuvenation. (Tonight he'll be seen both on ABC's "20/20" and a "PBS Late Night" rerun.) This just seems beneath the dignity of an idol, even a toppled one. And yet there's no reason to doubt Caesar's sincerity or that, with 20 years of drug and booze addiction behind him, he truly feels himself to be, in that time-honored phrase, A New Man.

For those who grew up to the tune of live television during Caesar's salad days, there was nothing wrong with The Old Man. When he starred in "Your Show of Shows" with Imogene Coca and "Caesar's Hour" with Nanette Fabray, Caesar's comic rampage really was incomparable and uproarious, week after daredevil week. Caesar lost his first sponsor, Admiral, because he was too successful; his show was selling television sets faster than Admiral could make them.

How old is Sid Caesar now? "Sixty," he replies with a broad beam. He is daring anyone to tell him he has not come all the way back from the brink. How old does he feel? "Thirty-five," he says, without a pause. He still talks very fast, zipzipzip, as if the words are swirling around inside and fly out like fresh popcorn. He looks tan, fit, and dressed for comfort, not taste, in saggy-baggy jeans with a huge belt buckle, a Lacoste shirt, and a smattering of Hollywood jewelry. He'd look awful if he weren't Sid Caesar.

Caesar will expound at the drop of a hatpin on the benefits of the therapy that brought him back to life and rescued him from the days when he threw violent temper tantrums at the slightest provocation, punched horses in the nose or passed out face first in a plate of cole slaw while having dinner with friends at a restaurant. It was that old devil insecurity that led him, he thinks, to addiction to alchohol and barbiturates, and turned what had been a skyrocket of a career into a disappearing act.

"I never believed in myself," he says now. "I never had any self-worth because even at the height of my success, I thought a certain power was doing this. It wasn't me. This power, I didn't know what it was, was doing it. And I was always afraid the power would take it away. Also, I'd never had any failure. I always went from success to success, in nightclubs, on Broadway, and then on television. I mean, one after the other; I thought that was normal. And then, when I was canceled, in 1958, the Earth opened up and swallowed me. It was like 'That's it. They finally caught on; they finally found me out.' "

The book is an answer to the question, asked by many over the past two decades, "What ever happened to Sid Caesar?" Despite occasional triumphs like his multiple-role performance in Neil Simon's "Little Me" on Broadway, he would usually turn up only halfheartedly on has-been get-togethers like "The Love Boat" or in generally shabby movies.

"Those 20 years!" he sighs. "I'd go out and get work--my body showed up but my brain wasn't there. I just punished myself endlessly. Endlessly, endlessly, endlessly." He made an entire movie in Australia ("Barnaby and Me") and just barely remembers even having been there. He calls Australia his "lost continent."

The endless punishment has ended, he feels certain. And he is able to look back on the helter-skelter days of his early TV triumphs with reverence and joy, just as those who sat at home and watched, and laughed, can do. Sid and Imogene may have been the most felicitous pairing since Fred and Ginger, at least in terms of generated pleasure. Even though it was a fresh show every week, certain themes and, inevitably, catch phrases would return again and again. Those who watched faithfully then can probably remember without much trouble the way Coca would exclaim, "It's a smallll world!" to Caesar, her voice as big and round as her eyes, or the particular way Caesar could put the all-purpose exclamation "Oh boy" -- sometimes "Whoa boy" -- through innumerable variations.

It was rowdy, but it wasn't really slapstick; there was usually a satiric edge, but not the topical kind. They didn't do topical comedy because they couldn't. Sponsor pressure forbade anything topical, Caesar says, and the mores of time prohibited the use of even the word "pregnant."

So in a way they were forced into creating timeless comedy that is as funny today, in most cases, as it was yesterday. Now it belongs to the ages, and to the Museum of Broadcasting in New York, to whom Caesar recently donated hours of old kinescopes. He also says there are tentative plans to package highlights from the old shows as syndicated half-hour shows, as has been done, or will soon be done, with such TV classics and semiclassics as "The Jackie Gleason Show," "Rowan and Martin's Laugh-In" and "The Red Skelton Show."

One of the striking things about Caesar's book is the way certain incidents he describes as harrowing sound something like the old domestic comedy sketches he used to do with Coca. He talks about flinging himself into mad outbursts, as when his wife Florence (truly the heroine of the book) once gently cautioned him that he was driving too fast and thereby made him so irrationally furious that he stepped on the gas and tore off maniacally down the freeway -- an "I'll-show-you" straight out of Caesar and Coca, but not played for laughs.

Or a time in Paris when he and Florence walked out of a theater into a rainstorm and Caesar blew up because he couldn't get a cab. Florence suggested they walk back to the hotel. From the book: "I said, 'You want to walk in the rain? All right. That's it. I'll show you walking in the rain.' And I strode off, down the Champs E'lyse'es." Caesar would do the same kind of yelling on TV, and people would roar with laughter. It's a context matter, obviously.

The pop-psychological explanation of the two Caesars, good and bad, is that they are alternate sides of the same craziness. It certainly took craziness, and not just the playful kind, to come up with 90 minutes a week of breakneck comedy. For every insane moment on the air, there was an insane moment backstage -- furious fights and fits of temper from Caesar and the brilliant writers who worked on the show over the years. Larry Gelbart, Woody Allen, Neil Simon and Mel Brooks, among others, worked with Caesar on those shows of shows.

They used to set each other's desks on fire and throw each other's shoes out the window.

"Well," Caesar says, "they always say, 'From a polite meeting comes a polite show.' We never had a polite meeting. I mean, when you have Mel Brooks trying to top Neil Simon and Neil Simon trying to top Larry Gelbart--I mean, you've got a lot of energy and power and brains going on there. It was like, really, a cyclotron in there. All the shows weren't great, but I would say we had a batting average of 750 out of a thousand."

Caesar has seen "My Favorite Year," the warm hit movie comedy about an early TV comedy show obviously patterned on Caesar's. "I liked the picture," he says. "I thought it was funny. I identified more with Peter O'Toole than I did with Joe Bologna, who played me." That's because O'Toole plays a compulsive and perpetual drunk.

One objection Caesar has to the way his character is portrayed, however, is that "nobody ever handed me a script. Ever." He wasn't handed a script because he wasn't just the star. He participated in every step of creation. Indeed, Caesar says he turned down a role in the current TV series "Cheers" because it was obvious to him the writers wouldn't let him contribute to the development of his character. He would have been expected to play the part as written. "I told them, 'Fine. You know what you can do with the script,' and I walked out. Twenty-five-year-old boys who were brought up on 'Gilligan's Island'!" No, TV comedy is not as funny as it was during the reign of Caesar. "The writers today don't say, 'You think this will get a big laugh?' They say, 'How big a laugh do you want to have?' Because they've got a machine that does the laughing."

"My Favorite Year" was produced by Mel Brooks' company, and Brooks was one of Caesar's first writers. He started on the show at $40 a week with no screen credit, but he got to work with the other young comic Turks in town. Selma Diamond, seen in the film as the costume coordinator, was actually a writer for Caesar in the old days; she became a performer later on Jack Paar's "Tonight Show." The movie opens with a recording of Nat King Cole singing just the verse of Hoagy Carmichael's "Stardust." The verse ends, "Love is now the stardust of yesterday, the music of the years gone by." That stardust and that music are lovingly remembered by the film and brought back by Caesar's reemergence.

In depicting the backstage mayhem on the show, "My Favorite Year" is apparently no exaggeration. According to Caesar, many of the legends are true. Fist fights did break out among disagreeing writers. Brooks was occasionally hanged in effigy for his notorious and unrepentant tardiness, and Caesar says that once in anger he picked young Brooks up by the lapels, carried him to the window, and dangled him outside, 18 stories above New York. And Caesar, whose physical strength was almost superhuman, really did once punch out a horse because it had thrown his wife.

Brooks remembered that incident and used it years later in his film "Blazing Saddles."

One recurring joke in the film is a comedy writer who never says anything out loud, instead whispering into the ear of a colleague who then tells the others in the room. In fact, Caesar writes, Neil Simon, now the world's most successful playwright, used to whisper into Carl Reiner's ear just that way, because he didn't want to fight for attention.

You didn't have to be crazy to work there, but -- no, you did have to be crazy.

Caesar says he has no firm prospects for the future, but would be willing to play a dramatic role about a character suffering the problems he lived through in real life -- if the term "real life" can be applied to one as unreal as his. According to the Hollywood trade papers, Caesar has just teamed up with Danny Thomas on a situation comedy project for ABC--not a terribly tantalizing thought, maybe, but Sid Caesar wants to work, especially now that he has Sid Caesar back again. "As I see it now," he says conclusively, "I'm going to be very happy."

Perhaps Caesar's Hour has only begun.