He learned most of his boxing "just street fighting growing up." Born 35 years ago on the Lower East Side to a Puerto Rican father and a Jewish mother, he was christened Gerald Rivers and hispanicized his name while in college. There are no scars on his ruggedly handsome face. With his neatly styled hair, easy smile, and air of casual masculinity -- one of his favorite outfits is a denim jacket over a T-shirt -- Rivera could easily pass for a professional athlete turned matinee idol. Yet it is primarily his literary ability, combined with a sentimentality backed up by facts, that has made him a type of media folk hero. His documentaries have earned him 78 humanitarian awards. In addition to his more than 3,000 news stories, Rivera has written four books, including one on Willowbrook. "I've been back there many times, and it still stinks -- literally and figuratively," says Rivera in his customary vibrant tone. "But it's now a much smaller place. Willowbrook started with 6,500 people, and now it's well under a thousand. It has become, in fact, one of the better institutions. But institutions are not the answer. There's no such thing as a good big institution." With his commitments as chairman of One to One, his heavy travel schedule for _20/20_, and his new daily commentary on ABC Radio, Rivera likes to spend free evenings at home with his wife Sheri at their apartment near Lincoln Center. A Westsider since 1975, he names the Ginger Man and the Cafe des Artistes as his favorite dining spots. Asked about the biggest difference between his present career and his earlier career as a lawyer, Rivera says: "Now I have the power to cause positive change in a dramatic way. When you have an audience of tens of millions of people, it's a multiple in terms of influence and impact, and the effective delivery of information. As a broadcaster, I've found that one person can make a difference." ******** WESTSIDER NED ROREM Author and Pulitzer Prize-winning composer 6-17-78 The world has always been fascinated by artists who excel in more than one field. There was Richard Wagner, for example, who wrote the words and the music to all his operas. Cole Porter and Bob Dylan are two others who have proven their mastery of both language and composition. But while these three men combined their talents to produce great songs, Ned Rorem has employed his musical and literary gifts in a different way. By keeping the two separate, he has gained a huge reputation as a composer of serious music and also as a prose writer of formidable style. In 1976 he won the Pulitzer Prize for music. And last month Simon and Schuster published his eighth book, _An Absolute Gift_.