Nobody loves a streak hitter, not even himself. Ask Mike Schmidt, the long ball addict of the Philadelphia Phillies, who has spent years fighting himself whenever he has suffered withdrawal symptoms from his home run habit.

"It's a frustrating life...just not satisfying," says the Gold Glove third base man, who, it might be supposed, would have the world on a string after hitting 206 homers the last six years - more than anyone else in baseball.

"Once you know how easy it feels to be rolling along, destroying everything in sight, it only whets your appetite. It's twice as brutal when you go back into the pits."

No major sport offers a plight comparable to that of the heaven-or-Hades hitter who never knows from day to day which direction he is headed: trotting around the bases or moping back to the bat rack.

Right now, Schmidt is on the homer high of a lifetime. After a cold-turkey season in 1978 with only 21 homers in 145 games, Schmidt is once more floating above the field like some light-footed big cat in a state of grace.

"I don't think it's humanly possible to be any better hitter than I've been for the last month," says Schmidt, whose dozen homers in his last 18 games have put him nominally ahead of the Ruth-Maris home run record pace with 35 round-trippers in the Phils' 99 games.

"I've been hot before, but never for this long. I catch myself thinking, "How can this go on?""

For the moment, Schmidt is a pitcher's nightmare - the 6-foot-2, 195-pounder who swings hard enough to hit every pitch 500 feet, yet makes contact like a careful slap hitter.

"My mind sees certain pitches before they're even thrown," says Schmidt, trying not to lick his chops publicly. "I've searched for years for a swing-thought that would allow me to stay within myself and just let my talent flow.

"Now, I've found it - I'm keeping the bat well back with my left shoulder kept tucked in. Lord, I wish I could hold that feeling forever. It's so intangible, that sense of letting success breed success," says Schmit, who seldom sounds as confident as a man should who has led the majors in home runs three of the last five years.

"There have been so many times over the years that I thought I wasted a lot of ability," he says. "I'm sick of one-month seasons. Of course, I've always wanted to put together one whole season just to see what my potential really is.

"Once you've done that, it must be easier to do it again."

Few players have suffered so long and silently through the traumas of a wildly erratic career. From that first Philly season when he hit .196, Schmidt has always known the game was a struggle.

Ironically, a glance at Schmidt's statistics seems to indicate a consistent and contented player: for the splendid, four-year period of 1974-77, he averaged 38 homers and more than 100 runs, RBI and walks as well as 20 steals.

Yet the brooding Schmidt, with a career batting average of .255 and a history of 130 to 160 strikeouts a year, was constantly demanding more of himself. When he wasn't, the implacable Philadelphia fans were. How well they knew that Schmidt was the only regular in baseball's history to have fanned more often than he got a hit.

By the end of last season, as he sat disconsolately in the losing Phillie locker room in the playoffs, he was an almost pathetic figure, a great player shouldering even more of his team's burden of failure than his postseason .182 career average warranted.

Even now, he cannot escape those memories.

"I sure haven't mastered this game, even if I feel like it right now," says the 29-year-old. "The big leagues teach you how temporary everything is. Baseball can turn around and go south on you awful fast."

But now, Phillie cynics bless Schmidt for keeping their injury-decimated team only four games out of first place with his single-handed slugging. No other Phil has more than 10 homers. But they also half expect Schmitty to find a way to go 0 for August.

A year ago, even he might have agreed. But not now.

"Last season I'd just about accepted the idea that I was a dead streak hitter and would never change," says Schmidt, who is in a race for the major league home run lead with that equally torrid creature of mood, Dave Kingman of the Chicago Cubs.

"All I could do was the same old thing: bear down on defense and draw some walks when I was cold so I wouldn't be useless."

Since then, Schmidt hopes that, in addition to minor swing changes, he has learned how to relax, think less and forgive more.

First, Pete Rose arrived to take the burden of team leader, hot dog and top salary earner off the sensitive Schmidt. Both welcomed the change.

"I've worked harder at practicing the Christian philosophy that I've always believed in," says Schmit. "I had to find some way to feel more serenity. Maybe nobody's at peace, but it helps me."

Perhaps the only thing that can keep Schmidt from reaching the 50s in homers, barring injury of course, is that longtime nemesis, Mike Schmidt.

"Just think what a great failure it would be not to take advantage of this," he says. "To blow these next two months would be pathetic. I haven't proved anything to myself or my teammates...we're in a pennant race, that's what matters."

Certainly, Schmidt is unlikely to continue batting .428 and slugging an even 1,000, as he has since July 7. In fact, he is currently in the first stages of ill fortune that can catalyze a classic Schmidt skid - he has hit rockets at fielders and hooked homers foul here for two nights, yet, since his 35th blast, has gone 0 for 10.

Like a summer storm, Schmidt clouds up quickly, then rains on everybody's parade. Already this year, he has had full-moon binges when he hit: five homers in four days in mid May, and seven homers in five days in July. That's 17 of his 35 homers in 13 days of streaks. Typically, he also has homered in four consecutive at-bats, making him the only man to do it twice in a major league career.

Schmidt should break the National League record for most homers through July, 36, but in a year of contradictory percentages when he has hit 24 homers on the road and 28 off right handers, he is not about to make predictions.

"Boy, I'm the last guy to talk about 61 homers," he says. "I don't even want to rap (talk) about it. It shows a disrespect for the difficulty of the game.

"I'm a player who's had to learn to take pride in drawing "ball four" and running down to first base with a walk."