For Tom Bosley, the bemused dad on ABC's Happy Days, the glittering Tony Awards ceremony last week was bittersweet. His selection as a presenter of Broadway's Oscar—along with such luminous colleagues as Jane Fonda, Jack Lemmon and John Houseman—acknowledged his prime-time prominence but was also a reminder of the legendary musical Fiorello! Bosley's performance 20 years ago as New York's famed (and lookalike) Mayor La-Guardia had won him not only a Tony but a wife—chorus girl Jean Eliot. Then last year, after a harrowing eight-year battle, Jean died of brain cancer at 45.

"We were kind of prepared for it," says Bosley, 51, who since February has been co-chairman of the American Cancer Society's Crusade for Education. "The adjustments started years before her death." He now travels widely raising funds, speaks nearly every week at Cancer Society meetings and does the TV talk show circuit. His heartfelt message remains the same: "It's all right to go on living your life after you lose a loved one." Tom feels his contribution is to talk candidly about how he and 12-year-old daughter Amy did—and did not—cope.

"When we learned Jean wouldn't be with us for long," Bosley says, "I made a couple of decisions. One was not to tell my wife [already suffering frequent epilepsy-like seizures], who wasn't emotionally capable of knowing the truth. The other was that the best thing for Amy was to tell her the total truth, which I did."

Bosley tried to provide emotional support for his daughter when Jean became "incapable of coping with any kind of relationship." For Amy, her mother's illness meant that for years "she couldn't have friends over to play and sometimes would have to eat alone," says Tom, who admits relief that "now she has become a kid again." Throughout his wife's long illness Bosley continued to work, although returning to the set of a TV movie just after her death was especially difficult. "In the first scene, a girl playing my daughter had to say, 'I wish Mommy didn't have to die,' " Tom recalls. The director wanted to shoot it later. "I said, 'It has to be done. Let's do it now.' " As a remembrance of his wife of 16 years, Tom wears around his neck a pendant that he bought on the first anniversary of her death.

Bosley—usually as easygoing as his Happy Days character—learned a thing or two about adversity while growing up in Chicago. He was the younger son of a real estate broker father and a former concert pianist mother. "We were fairly wealthy until the stock market crashed," Bosley says. "When I was 2, my father lost all his money." His parents divorced nine years later. Bosley joined the Navy in 1945 at 17 ("I'm the only guy I know who went in as a seaman and came out a seaman"), then enrolled in pre-law at De Paul University. In his first year he switched to acting.

After stock theater in Illinois (with fellow aspirants Paul Newman, Geraldine Page and Shelley Berman), he flipped a coin in 1950 to decide between New York and Los Angeles. New York won. For nine years before Fiorello! he acted off-Broadway and in summer stock while working menial jobs to feed his not-inconsiderable self (now 5'9", 213 pounds). He later co-starred in such movies as Divorce American Style and The World of Henry Orient, and on TV in The Debbie Reynolds Show and The Sandy Duncan Show. Today commercial and cartoon voice-overs and such TV roles as Ben Franklin in The Rebels supplement his six-figure sitcom salary. "In the beginning of Happy Days, the kids would ask, 'What should I do with the money I'm making?' " Tom says. "Now I go to them for advice."

His investments include his four-bedroom hilltop house in L.A.'s Tarzana Hills near the local country club, where he plays golf and tennis "badly and occasionally." He has season box seats for Dodgers games. ("Tommy Lasorda yells at me for still being a Cubs fan.") He is also cautiously trying a new pastime—dating—despite his worry that "of the three ladies I go out with, I think I'm as old as their parents, if not older." Older, but not necessarily wiser, he adds. "It's a tremendous frustration," Bosley admits. "I find I'm making the same mistakes at 51 I made at 21. Jesus, haven't I learned anything in 30 years?"