They say you can get too much of a good thing. Don't believe 'em. As tens of thousands of Redskins fans attested yesterday on Pennsylvania Avenue, a wise fan doesn't pass up a chance for joy. You never know when the parade will pass again, or whether the people at its head will be so worthy of your cheers.

These days, it's easy to forget how few and far between such moments of civic celebration, and self-approval, can be. In the last decade, we have honored the Redskins after three Super Bowls, the Washington Bullets after two NBA finals, the Georgetown Hoyas after three NCAA finals and Sugar Ray Leonard who knows how many times. A bit sheepishly, we even feted the semi-adopted Baltimore Orioles at the White House after a World Series.

Not only were all these folks world champions but (and what are the odds on this) they were all winners who stood for estimable values. Doug Williams just continues the tradition of Wes Unseld, Abe Pollin, Joe Gibbs, John Thompson and Leonard. Not a George Steinbrenner in the bunch.

Our Washington expectations have risen so high that, on a rather wistful note, Redskins General Manager Bobby Beathard looked out at the noontime crowd yesterday and said, "You people don't know it, but you're putting more pressure on us to come back next year."

Perhaps you had to grow up in Washington from the mid-'50s until the early '70s -- a period of total sports blight -- to appreciate what's happened to this town's public games. Back then, it was a good year if the Senators didn't leave town. A different pro basketball franchise went belly up every time it snowed. A child raised on the strategic acumen of Cookie Lavagetto and Joe Kuharich had much to overcome.

Even more depressing, the lessons of sport were mostly negative then. The best your parents could tell you was not to be a racist like George Preston Marshall or a money-hungry cad like Calvin Griffith or a carpetbagger like Bob Short.

Now, that's all changed. Leonard and Mike Trainer have redefined the very nature of the modern manager-fighter relationship in boxing, proving a nonexploitative deal is possible. Pollin has epitomized patience in ownership and, in both his franchises, hired top people you could take home to mother. Thompson hired the first woman assistant basketball coach, then made her the first full-time academic adviser in that sport. Beathard and Gibbs replaced the chicanery of George Allen with surfing and Sunday school. Hank Peters and the Orioles meant family and good sense in baseball.

In the '50s and '60s, no child of Washington ever dared to dream of the sorts of celebrations that now seem an annual ritual. Now, people compare these civic orgies, debating whether the horns blew later into the night for Super Bowl XVII or XXII. Was the 35-point quarter in San Diego a bigger shock than Sugar Ray over Marvelous Marvin Hagler?

If we're not saluting Napoleon McCallum and David Robinson as paragons of the student-athlete- soldier ideal, then we're working our way toward the conclusion that the Washington Capitals probably will win the Stanley Cup this year or next because . . . well, because it just feels like it's time, so we'll just sit back and watch it happen.

For decades, all Washington's sports luck seemed to be bad, sometimes even tragic, as with Vince Lombardi and Ernie Davis. Now, who's more fortunate when it counts? The town's logo ought to be a four-leaf clover.

The Redskins didn't want to play the 49ers in San Francisco to open the playoffs, so, the Minnesota Vikings made that avoidance a reality by upsetting New Orleans. Next, the Redskins wanted to play the Vikings in RFK Stadium rather than the mean old 49ers on the road. So, darned if the Vikings didn't upset San Francisco. Finally, the Redskins really wanted Minnesota to return to form and stop playing over its head. So what happens? The Vikings come to D.C. and they can't catch a cold. That's 10 years worth of playoff breaks in a month.

Once upon a time, if a Washington youngster wanted a hero, he could pick between Eddie LeBaron and Roy Sievers, Frank Howard and Norm Snead. After that, squat. Now, you get your choice of heroes -- a legend of the month. As soon as a John Riggins or Joe Theismann leaves, a Moses Malone or Bernard King arrives. Patrick Ewing and Ralph Sampson leave, but Brian Williams and Alonzo Mourning arrive.

Everybody gets so revved up that Jack Kent Cooke and Edward Bennett Williams, two of the last men on earth who ought to be asking taxpayers to build them anything, not only have the brass to ask for new ballparks, but may have their wishes granted with barely a horselaugh in the house.

These are the good old days. We would do well to focus on them. Not only is Washington winning in its games on almost every front, but, for the most part, winning in just the right way.

Perhaps the closing minutes of Super Bowl XXII captured the precarious but exhilarating peak that Washington has reached. The Redskins, ahead 42-10, were driving to run out the clock. One more touchdown and the Redskins would set records for most points and largest margin of victory -- the gaudiest Super Bowl win of all.

And there was Joe Gibbs, doing everything in his power not to run up the score against an old friend, Coach Dan Reeves. First, Gibbs stopped calling passes. But the poor demoralized Broncos were still helpless. So he stopped changing plays, just running Counter Gap every time.

Many Washingtonians have waited a long time for this town's golden age of games. It's twice as nice that so many of the people at the head of our parades have been worthy of the ride.