MICHU IS 33 inches tall -- the Smallest Man in the World. He is 43 years old, weighs 25 pounds, wears a size 3 shoe. His full name is Mihaly Mezaros, and when he was born in Budapest he weighed 2 1/2 pounds and was 14 inches long.

The sideshow, for which the legendary P.T. Barnum packaged real and fake in the same bluster, is gone now. Ringling Bros. and Barnum & Bailey today is shrewdly devoid of snake oil. It is a circus of athletics and achievement, mobile as vaudeville but more clever, so that television still has not caught up and devoured it.

Once the sideshow was a great draw, but now its absence is almost a relief. Perhaps the taste for freaks declines in a people gorged on war, famine and the results of thalidomide. The bumpkin in us is expunged, and we no longer gape innocently but struggle to explain. This circus mirrors the best in us all: the quadruple somersault, the taming of beasts, the marvel of the teeterboard, the confidence of the daredevils. In today's Ringling Bros. and Barnum & Bailey, man is in his element, apparently perfectable.

Mihaly Mezaros is believed to be the smallest human known. In the circus, he rides a tiny cart, waving gaily to children taller than he; later he appears with his trained poodle act, and appears again as a comically tiny Tarzan, swinging to the rescue on a vine.

He is not in a sideshow, but the center ring.

"When I was born, my parents were working in Lilliputian Theater in central Budapest," Michu began in his Donald Duck voice, pausing to light a long cigarette high in the empty grandstands of the Charlotte, N.C., Coliseum. "This was like a zoo park, you know? Lots of different shows going on, just like Great Adventure. Country people coming up to see it. Thirty people living in the Lilliputian House. My brother and sister were in the same business, too."

But then the war came and "the bombs fell. Everything was gone." He shrugged, a tiny gesture.

After the war, Michu, with other children who were dwarfs, attended a state-run circus school that taught juggling, pantomime and acrobatics as well as traditional subjects. "Ah, it was not too bad. Everybody was small, but the director and the teacher were taller guys. I lived in circus wagons pulled by horses. Later on they were pulled by a tractor, but it was same wagon. We went city to city, all over Europe."

For 15 years he traveled, working as a clown, unicylist, announcer and dancer for a small Eastern European show, "all that time sleeping and dreaming that I would come to United States."

To converse, Michu must look up. From this debased position he has learned to counter with a wisecrack. A new companion, presented with the disparity in height, is unnerved. The advantage, on first meeting, is Michu's. Otherwise his advantages are few.

He is a midget--a term the circus reserves for dwarfs of normal physical proportions. (Achondroplastic dwarfs, in whom cartilage has failed to develop normally, have heads of near-normal size and a characteristic rolling gait.) Human size is controlled in part by the growth hormone, which is produced by the pituitary gland. In congenital isolated growth-hormone deficiency, the body proportions can be miniaturized but the appearance of normality preserved. Primordial dwarfism, the causes of which are not well understood, can produce miniaturization with complete normality. Michu does not know the clinical explanation for his condition. His father and mother, Ganos and Margarite, and his brother and sister, also named Ganos and Margarite, were midgets, too. All were about 42 inches tall. Charles Stratton, whom Barnum exhibited as "Gen. Tom Thumb," was 40 inches tall as an adult--seven inches taller than Michu.

His fellow performers give Michu a wide berth. He once was knocked down by an acrobat rushing to make a cue and was a week recovering. He is barred from strolling the streets of large cities because of the danger of accidental trampling. In crowded circus conditions, arrows sometimes are taped on the floor to guide him, since his view of landmarks often is obscured. Large pets and ebullient children present a physical threat at all times.

Charly Baumann, the tiger trainer, picks Michu up and places him at eye level for a man-to-man talk. For most, however, that would be an act of unacceptable intimacy. Women who have tried it have found, in fact, that Michu responds with acts of unacceptable intimacy. He also bites, and has a habit of punching circus people behind the knee to announce his passing. He smokes cigarettes and cigars and drinks French brandy, sometimes excessively. A skilled mime, he is capable of devastating parody to which there can be no effective rejoinder.

For these reasons, it is said by persons in the circus, Michu keeps to himself nowadays.

Michu has applied for U.S. citizenship. He is sure it will be "no problem. I have a good lawyer in New York."

When he first arrived in New York City he was very impressed. ". . . Empire State Building, Madison Square Garden, I was counting floors on the elevator until we got to the 18th floor," Michu said. "I look down, everything is very small. Small cars, small people. Looks like tiny little matchboxes--unbelievable."

He shrugs again, laughs his brittle laugh, waves away the memory with a hand. "Later on, everything becomes normal. You know, in Europe it was one ring, in a small tent, maybe there were 700 people. Here we play the Superdome. It's The Greatest Show on Earth. I don't even know everybody's name. Naturally I know their faces.

"I like everybody, sure. The first time I met Charly Baumann I said, 'Sieg heil!' Ah, ha ha ha ha ha ha! But this just because I don't speak English then. I speak German, Yugoslavian, Polish, Bulgarian, some Russian."

Michu is a bachelor, but he has been married more than 1,000 times in the center ring in an act that ran for more than two years.

"It was a big celebration every time," he said. "We were the smallest people ever to get married in the circus. Such a beautiful show. A long time ago General Tom Thumb got married and it was a very popular act. That's where the idea came from.

"But it didn't work out. She had never been with the circus before, and when I said try it--come with us--she already had a good job in a factory in Hungary. She couldn't enjoy moving all the time with the circus. She was never in a Lilliputian house, like I was, and she was starting out past 20 years old. I wanted to keep working together, but after two years she went back to Hungary.

"Hey, good luck to her. Bad luck to me."

Irvin Feld began to hear about a very small midget, the smallest midget in the world, in the early 1970s. If such a man existed, he was determined to get him for his circus. By 1971 he had narrowed the search to Hungary. In 1972, the Hungarian government confirmed the existence of such a man, but declined to let Feld meet him.

Feld is a dapper entrepreneur-impresario in his sixties who wears thick eyeglasses and smokes thin cigars. He makes several trips yearly to Eastern Europe, auditioning performers. "You don't just go to the circus over there," he said. "That's not the way it works. In Sofia, in Bulgaria, my son Ken and I sit down and 70 or 80 acts parade in front of us for days. Then when it's over, I take my pick. Same thing in Bucharest, Romania. The Russian circus is marvelous, too. They have 500 units all over the world. But the Russians will only let their acts out for 13 weeks, and that's not enough for us."

In Box Seat A1 of Section 11, the best circus seat in the Charlotte Coliseum, Feld recounted how he finally hired Mihaly Mezaros. Meanwhile, the circus went on full blast in front of him--very full blast, because Feld is not only the boss but a connoisseur of circuses, and if he is not pleased heads--and visas--will roll.

"Finally I said to the Hungarians, 'Look, either you show us this man or we pass on all Hungarian acts. We're just not going to buy anymore until we see him.' Then we go back to the hotel in Budapest. So they send a car and driver at 10 o'clock at night. Ken and I get in the car, and we drive and drive and drive. Snow had just fallen, and the roads were lousy, and I began to get furious. I thought they were taking us for a ride. But eventually, after a long time, we came to a small village and stopped in front of a row of tenement houses, nine or 10 of them. There were some lights on upstairs. A guy leads us around to the back of the houses.

"Now at this time, I had just about no peripheral vision in my eyes at all. We were being led up these back steps, and suddenly there's two big green eyes staring at me, very close. We get to the top, and walk into a room. There's a python on the floor. All of a sudden, whoosh!, something runs between my legs. And that's how I met Michu. There was a bottle of brandy, and we talked. You should have seen the longing in his eyes when I said I needed him at Madison Square Garden.

"It turned out that the green eyes were a bear's. That's right. They also had a porcupine in there, and a python. What it was, was a scab unauthorized circus. That's the reason the Hungarians wouldn't show him to me before."

Michu talks on. It is part of his job, talking--like swinging on the vine or training poodles. He can talk in many languages. But what can he say? What is the correlative? The acrobat says, explaining his art, that "to spring very hard, that's the secret." The tiger trainer says, with convincing bravado, "some people are born to do it." But to confront Michu is to realize, almost at once, that there is no legitimate question. To the illegitimate questions--should we wish to pry into the private life of a 33-inch man--he responds mysteriously, in teasing sentences without verbs, with raised eyebrows, with inexplicable jigsaw pieces of disinformation: "I don't like trouble many times. Just sometimes." Or, "Not everybody perfect. Not everybody stupid."

His biographer, if he has a good one, will have to study equally the rest of us: the tall guys who think the universe was invented for them, waist-high and convenient. Michu thinks of himself as one of us ("no problem"), but it is not easy to respond in kind.

"It's okay." Michu said. "I'm happy. I have mobile home, generators, a barbecue. I like fishing. What I do is show business. Like comedy, really. I'm a good mime, they say? Thank you very much. To do it you must learn to observe people closely. No problem for me, I'm a professional.

"Really, I feel like a regular person. A life is a life. A job is a job. A paycheck is a paycheck. Take the paycheck and shut up. That's from Mr. Feld. Ah ha ha ha ha ha ha ha!"Tomorrow: The 12-Year-Old Girl On the Galloping Horse