One of corporate America's famous boy wonders turned 60 yesterday. It made some people a bit nostalgic, including the boy wonder himself.

"Looking back now I can see it was flattering," said Sen. Charles H. Percy (R-Ill.) of the label once automatically attached to his name. "But when you're a corporation president and still being called a 'boy,' well, at the time I wanted to look as old as I could."

Nobody called him a boy yesterday though the still boyish-looking senator had a little trouble passing for 60 at a party given him by his U.S. Senate staff.

"I never heard of anyone before who had a birthday protraying himself older than he is," said Sen. Paul Sarbanes (D-Md.)

"I hope I'm that young looking when I get to be his age," said Sen. William S. Cohen (R-Me.), who's only 39.

"Well, just how old does 60 look?" wondered Sen. Harrison Williams (D-N.J.), about two months shy of that milestone himself.

When Sen. Strom Thurmond (R-S.C.) arrived, Percy let go a shrill whistle to get everybody's attention.

"This is the man who is constantly aging me," he said of his U.S. Senate seatmate. "If I have grandchildren, he has children."

"And one of these days," shot back Thurmond, who will be 77 in December, "I may give him the secret."

Percy's executive assistant, Nadine Jacobsen, who has been with him since he was chairman of Bell and Howell Co., organized the party and come up with the idea for the staff gift: a Blue Ridge Balloon ride from Bristol, Va., for "however long the wind lasts."

"So what else do you give a U.S. senator who has everything?" mused an aide.

It seemed to be endemic. About 40 of Percy's Senate colleagues stopped by EF 100 in the Capitol and had anybody been adding up personal fortunes in the room just for kicks, those of Howard Metzenbaum (D-Ohio), Malcolm Wallop (R-Wyo.), John Warner (R-Va.), Bill Bradley (D-N.J.), John Danforth (R-Mo.), Jacob Javits (R-N.Y.), S.I. Hayakawa (R-Calif.), Barry Goldwater (R-Ariz.), Lloyd Bentsen (D-Tex.) and Percy would have totaled a cool $75 million.

Percy had gotten his (variously estimated between $5 and $10 million) by starting to work at age 7. By age 29, a young widower with three small children, he had been elected president of Bell and Howell.

"I really questioned the board about it -- whether it was wise for me to do that at that age. They said do it and put the children first," Percy recalled.

Joining Percy at last night's Capitol Hill celebration were Lorraine Guyer Percy, whom he married in 1950, and two of his four children -- Roger of Seattle, Wash., with his wife Penny, and Sharon Percy Rockefeller of Charleston, W. Va., with her four children. Her husband, Gov. Jay Rockefeller, was unable to make the trip.

It used to be a Percy credo that "the fun out of life is to set an objective and then go about accomplishing it." And while that's still somewhat true, the emphasis seems to have changed a little.

"I've no political ambitions beyond this," said Charles Harting Percy, once considered a strong contender for the Republican presidential nomination who didn't mind saying so. "I love the United States Senate. I think Illinois is a terribly exciting state to represent. And with that he picked up 10-week-old Justin Rockefeller, "a wonderful, wonderful little boy."