"Youth and greed have been my problems," said Skeets Nehemiah yesterday, reflecting on the chastening experience of enduring seven months of deteriorating health that have brought him influenza, asthma, bronchitis, weight loss, general weakness and, now, walking pneumonia.

"I took my youth for granted" said the world's greatest high hurdler. "I thourght I could get away with anything as long as my adrenaline was pumping.

"I figured nothing could go wrong, that I could win and win," said the 20-year-old University of Maryland junior who placed second in voting for the world track athlete of the year in 1979 after setting seven world records.

"People like Charles Foster (veteran hurdler) told me that sooner or later that being to cocky and too greedy would catchup with me. But I was too blind to see it," said Nehemiah, who begins his season by running in the National Invitational tonight at Cole Field House.

"It look 18 months to catch up with me, but it did. I learned a lesson, I hope I learned it in time," said the clean-living Nehemiah, whose shaky health frightens all those near him.

"I'm human."

Nehemiah's appearance in tonight's meet is typical of the crises of conscience that he has been going through for a year. How much should he run? Where should he travel? When should he say a firm no' to the multitude of meet directors, fans, interviewers and hangers-on who pluck at him?

Only three weeks ago, Nehemiah learned that he had had walking pneumonia for a month. He still has the remnants of it.

But, he says, he will run the 60-yard high hurdles at Cole tonight.

I'm still in the tail end of the pneumonia. It will drag on longer than it should because I am training and now I'm going to start running competitively again," he said.

"I got to get my feet wet again," he said, perhaps an unfortunate metaphor for a man with pneumonia. "I think I owe it to the school to help the meet.

"But I have a funny feeling about it. I can't believe that the CYO is here already. Only three weeks ago, I was sick," said Nehemiah, whose condition was serious enough that Maryland coaches considered hospitalizing him indefinitely.

"Before I know it, I'm in a meet.

"But, I think it's the right thing. I've been out a long time and I have to get going again." He has not run since winning the World Cup last August.

Has Nehemiah really learned his lesson? That is, at the least, a moot question concerning the slender young man whose health has broken down seriously three times in the last year.

If Renaldo Nehemiah, 6-foot-1 1/2 and 170 pounds, operates on the subconscious assumption that he is superhuman, it is extremely easy to see why. s

"Skeets is, in my opinion, the greatest athlete that has ever been born," said Stan Pitts yesterday.

If he had 10 different bodies and could train each of them differently, he could hold the world record in 10 different track events," bubbled Pitts, men's assistant and women's head coach's at College Park.

Nehemiah -- a hard worker, meticulous dresser, poised speaker and handsome young man -- is constantly surrounded by such all-but-giddy evaluations of his talent and temperament. He is accustomed to being described by nothing less than superlative adjectives. He expects perfection of himself in everything from grammar to grooming to games.

When asked if he could win the decathlon in the 1984 Olympics, he shrugs and says, "Maybe."

What he means is, "Sure, why not?"

Yet, within the courteous, almost courtly, Nehemiah exterior is a solitary and somewhat ruminative nature.

"We have never completely understood him," said Pitts. Sometimes, he floors us.

It's almost impossible to pin him down on anything. You have to put a long-range plan in front of him and make him agree to it, because on the spur of the moment he will always change his mind, one way or the other depending on how he feels at the moment.

"Sometimes, he's like a deer that will shy and run away into the woods."

"I've seen TV crews from major networks come down here from New York for interviews that he's agreed to and they'll spend $3,000 setting it up," said a Maryland official.

Skeets will arrive and just minutes before air time he'll look at all that equipment and, before you know it, he is in his car and gone. And when Skeets bolts, nobody can find him.

"You'd think that makes him a bad guy, but it's not true," said Pitts.

"He's just under constant enormous pressure and sometines he flees out of an instinct for self-preservation."

Trying to track down the elusive Nehemiah makes for some bizarre moments. He leaves a wake like a wild animal, or a fugitive leaving a trail of clues.

This week, a Maryland coach and a reporter spent two hours trying to locate Nehemiah on campus. "I'm completely confussed," said the coach. "Everywhere we go, Nehemian has just left."

In College Park, Nehemiah is noticed wherever he goes as though he were a human meteor shower. "Skeets' car was here a minute ago . . . Gee, I saw him at lunch . . . Isn't he in the weight room . . .?" go the progression of clues.

Everyone has seen him and no one knows where he is.

As it proves, Nehemiah is actually fleeing. "Skeets doesn't want to talk and he's not going to talk," said the coach finally. "He will dodge anyway he can. He's too polite to say 'no.' But he's elusive enough not to be cornered.

Nehemiah is a puff of smoke that disappears at will, then reappears at points and times of his own choosing. Chase him, and you will never catch him -- it is almost a point of honor. Stand still, give up, and suddenly, the phone will ring.

"Hello, this is Skeets Nehemiah," says the precise dignified voice. I'm sorry it took so long to get back to you."

Nehemiah is an untrappable creature that will walk up to the pit and voluntarily jump in if he is wooed with sugar. Naturally, everyone who wants something from Nehemiah courts him with honey and entreaties. And, Nehemiah keeps jumping into pits.

"I've had to learn a lot about myself in just a year," he said yesterday.

"I've never been sick or had my body let me down before.

"I've never had any of this happen to me before," he said, recalling the Pan An Games when he had a 103-degree temperature for five days, then, four days later, ran another record time coming out of a sick bed.

"I haven't properly taken care of my body and it almost cost me the World Cup," said Nehemiah, who won by an eyelash in Montreal, despite being 10 pounds underweight after galavanting from Zurich in Berlin to Nice for three meets in four days.

Nehemiah's infinitely changeable nature -- his ability to learn lessons in the abstract but not follow them in practice -- is the biggest worry he causes his friends.

For instance, who guides him, if anyone? At Maryland, it is Coach Frank Costello. At the Pan Am games, it was former hurdler Wilbur Russ. fAt Montreal, it was Farleigh Dickinson Coach Russ Rogers.

Can Nehemiah stick to a tough decision, once he makes it? Or can he be swayed by pressure and persistent nagging?

No one knows.

This summer, he said it was possible that he might drop out of Maryland's spring semester to train exclusively for the Olympics. Then, back in Costello's sphere of influence, he said there was "no question" but that he would stay at Maryland.

Two weeks ago, with tape recorders running at a New York press conference, he said he was thinking about dropping out of that spring semester again. But, a week ago, he said, "I'm staying in Maryland. I don't know how these rumors get started."

Nehemiah has already given Maryland more in free publicity than any college could ever give him. Obviously, his Olympic plans should override any other schedule decision. And outside a tiny coterie of track nuts, the world is indifferent to whether Nehemiah stays in school or takes a training break.

Yet, to Nehemiah, it is another crisis, another tough decision ot make with people pulling him in several directions.

If Nehemiah does not change his mind, if he, indeed, ignores his shakiness, his lack of training and the remnants of his pneumonia, and does race in the meet tonight, it will serve as the perfect symbol of his perplexing young life.

Where do his allegiances lie? What are his priorities? What is the wise course of action?

Of all the world's athletes, none seems, on past record to have more of an inside track on an Olympic gold medal than the graceful and elegant Skeets Nehemiah.

And few seem in more danger of becoming derailed.