BEVERLY HILLS, CALIF., FEB. 6 -- Ronald Reagan, who by his own admission is rarely introspective, was in a nostalgic mood this week as he looked back upon an improbable life that led him from the small towns of central Illinois to careers as a sports announcer and movie actor and, finally, to the highest office in the land.

The occasion for his reminiscences was his 80th birthday, celebrated tonight at a lavish flag-waving affair suffused in the glow of past glories and the mists of present patriotism.

The ceremony here, in which former British prime minister and "special friend" Margaret Thatcher shared top billing with Reagan, was conducted in an atmosphere of patriotic fervor marked by the playing of a San Diego Marine Corps band and a rendition of "God Bless the U.S.A.," which became a Republican anthem during the '84 campaign, led by the song's composer, Lee Greenwood. Videotaped greetings were sent by President Bush, Canadian Prime Minister Brian Mulroney and Polish President Lech Walesa.

"I would like to use this occasion to make a birthday wish," Reagan said after blowing out eight candles on a four-tiered cake and getting some of the icing on his tuxedo. "My wish is that God will watch over each and every one of our men and women who are bravely serving in the Persian Gulf -- and their families, wherever they may be -- and may they know that we as a nation stand firmly behind them."

The evening ended on an emotional note with Reagan and Nancy leading the nearly 1,000 guests in singing "God Bless America."

Earlier this week, during an interview in his 33rd-floor office in nearby Century City, his nostalgia was tangible. Reagan had replaced a borrowed Western landscape behind his desk with an oil painting sent him by an admirer that showed the Rock River outside Dixon, Ill., near the spot where a young Reagan, during three years as a lifeguard at Lowell Park, rescued 77 people from drowning.

Reviewing a life in which, said the former president, "most of my dreams came true," he talked about his boyhood as if it were yesterday and cheerfully agreed that it was "remarkable" that anyone of his particular background had become president of the United States.

Being president had not been one of his dreams, Reagan said. As he recalls it, in an account that differs from other known versions of what happened, he was dragged "kicking and screaming" into running for governor of California in 1966 on the basis of his successful fund-raising speech for Republican presidential candidate Barry Goldwater in 1964.

Reagan's highly dramatized versions of events in his life were interspersed with shrewd observations about his career. He said, for instance, that the wealthy entrepreneurs who had sponsored his entry into politics had never cared or even asked if he would be a good governor but had backed him chiefly because "they were convinced I could win."

Reagan praised President Bush's conduct of the war, referred to Saddam Hussein as "a monster" who must be expelled from Kuwait, and predicted that the American people would continue to back the United Nations military coalition against Iraq even if U.S. casualties mount during a ground campaign.

He also extolled Gen. Colin Powell, the chairman of the Joint Chiefs of Staff and the sixth of Reagan's national security advisers. He said of Powell, "I have the greatest respect and admiration for that man," and added in response to a question that he thought Powell had the qualifications to one day become president.

"I could see him in that office, yes," Reagan said.

He said he was particularly appreciative of the support given him during his presidency by Thatcher and of her attendance at the dinner tonight. He said that British Conservatives had made a "mistake" in ousting her -- "she did great things for her country."

Thatcher has been friends with Reagan since they were introduced in London in 1971 by the late Justin Dart, an early Reagan financial backer. Her visit here to attend Reagan's birthday celebration was her first trip outside Britain since she resigned as prime minister last November after it became clear that opponents within her own party had the votes to oust her.

Paying tribute to Reagan as the featured speaker tonight, Thatcher, wearing a long gold lame' skirt and a jacket trimmed in black velvet, said of him, "His is not, of course, an altogether typical American life -- not even in this great republic can every poor boy grow up to be president -- but it is the ideal American life."

Thatcher said that Reagan's "abiding" contribution was that he "set out to enlarge freedom the world over when freedom was in retreat," adding with a look at Reagan, "and you succeeded -- with perhaps a little help from friends." She particularly praised the Reagan defense buildup, which she said was wrongly criticized as wasteful and too expensive.

"How ill-judged that criticism looks today," she said, to loud applause. "The defense budgets of the 1980s, which you and Cap Weinberger pushed through against great odds, have provided President Bush and the armed forces with the sophisticated technology which at this moment is engaged in defeating aggression.

"Twenty-five years ago, in a famous speech," she said to Reagan, "you quoted President Franklin Roosevelt, who said we all have a 'rendezvous with destiny.' Certainly you had such a rendezvous. Thank God you were on time."

In saluting Reagan, she said, "Mr. President, I am proud to have been beside you when you held high the torch of freedom."

Bill Garber, Reagan's spokesman, said that the former president's office had been deluged with flowers, candy and other gifts. Reagan also received congratulatory phone calls from a number of national and world figures, including former president Richard Nixon, Colin Powell, Secretary of State James Baker, German Chancellor Helmut Kohl and South Korean President Roh Tae Woo. In the interview, Reagan noted he had received a letter of greetings from Soviet President Mikhail Gorbachev. Asked how he thought Gorbachev was doing, Reagan expressed support for the Soviet leader but said he was hampered by his "bureaucracy," a comment similar to one he made in response to a question by a reporter during his summit meeting in Moscow in 1988.

Reagan, looking back on his life from the high plateau of 80 years, said his earlier acting career had been crucial to his ability to perform as president.

"I found myself wondering in certain situations how you could do the job without being an actor," Reagan said. "An actor's whole stock in trade is the audience, the people. Your whole life is devoted to pleasing and serving the people who are going to buy tickets to see you. Well, there's a certain similarity in government. Your stock in trade is the people you serve."

Reagan said he believed that "a great many politicians" come to resent their constituents because "they have to please them in order to stay in their positions." But Reagan said he had developed "an affection" for the people and never resented them.

Tonight's black-tie dinner, which raised $2 million for the Reagan presidential library, was held with one eye on the Persian Gulf War, where the coalition forces are as staunchly backed by Thatcher as by Reagan. On Monday, during a tour with Reagan of the unfinished library, Thatcher expressed "great confidence in the ability of our military commanders" to remove Iraqi troops from Kuwait and said, "Any tyrant must know that this is the response with which he would meet."

The audience was drawn from the two worlds of entertainment and government in which Reagan had served. A political supporting cast included Vice President Quayle, California Gov. Pete Wilson, former senators Paul Laxalt and Howard Baker and Cabinet members from both the Reagan and Bush administrations, among them George Shultz, Caspar Weinberger, Jack Kemp and Samuel Skinner. Hollywood was represented by Elizabeth Taylor, Tom Selleck, Charlton Heston, Liza Minnelli, Eva Gabor, master of ceremonies Merv Griffin and longtime friend Jimmy Stewart, who was to make the birthday toast.

The common denominator of those attending was that they were well-heeled. Even the least expensive tables of 10 cost $10,000, a fee taken in stride by the entrepreneurs long accustomed to bankrolling Reagan campaigns. The more expensive tables, also for 10, went for $25,000.

For many of the supporters who attended tonight's event, this was a small price to pay for dining with a man who in Southern California has attained the status of a legend -- and one who is exceptionally well preserved. Except for the streaks of gray in his black hair, Reagan seems to have aged little since he left the White House. He looks particularly well for a man who in the past decade has survived a would-be assassin's bullet, two cancer operations and a post-presidential fall from a bucking horse that required the draining of fluid from his brain.

According to Reagan, his only recent health problem occurred a few months ago after he complained that something he had eaten had disagreed with him and doctors put him on a liquid diet. Reagan said they found nothing wrong with him. The "wonderful" thing about this ailment, said the ever-optimistic Reagan, was that the diet enabled him to lose 10 pounds around his waistline that he has been able to keep off.

Now, more than two years out of office, Reagan continues to be politically active. He made 29 appearances or videotapings for Republican candidates in the 1990 campaign and will give a speech in Arizona later this month for Fife Symington, the GOP candidate in the gubernatorial runoff election.

Told that the Arizona race was tight, Reagan said, "I'd like to tip the balance."

During his reminiscing, Reagan took a customary swipe at the "ill-advised" 22nd Amendment, which limits presidents to two terms in office. But he said he didn't miss the White House, except for the weekend trips to Camp David.

"Once in a while on television, I'll see a shot of Camp David and get a nostalgic feeling," Reagan said. "Pat Nixon had told Nancy before we got in office, 'Use Camp David. If you don't, you'll go stir crazy.' When you're living in the White House, it's wonderful, gracious living, but you look out at people walking on the street and know you can't walk on the street anymore. And then suddenly at Camp David, you're in that enclosure in the beautiful Catoctin national forest, living in a normal house, and it has a whole different atmosphere."

According to Reagan's friends, he is devoting far more time to following the course of the war in the Persian Gulf than to reminiscing about his life and presidency.

Reagan said he was particularly pleased at the success of the U.S. Patriots used to defend against Iraqi Scud missiles and hoped this would give "new life" to the Strategic Defense Initiative that he sponsored. While the technology of the Patriot is different from most of the technologies envisioned by SDI, which is designed to be used against intercontinental ballistic missiles, Reagan said his emphasis on missile defense had "given momentum" to converting the Patriot from an antiaircraft weapon to an antimissile one.

"There's never been an offensive weapon created that a defensive weapon wasn't eventually invented that could stop it," Reagan said.

In brief remarks tonight after the crowd had sung "Happy Birthday," Reagan repeated one of his oldest jokes, borrowed from comedian Jack Benny, about birthdays after 40. "I stopped having them {birthdays} quite a long time ago," Reagan said. "I simply have anniversaries of my 39th birthday. So this is my 41st anniversary of my 39th birthday, thank you."

Reagan was effusive about only two people -- Thatcher and Nancy Reagan, of whom he said, "Put simply, my life really began when I met her and has been rich and full ever since."

Of Reagan's four children, two by Nancy and two by his first wife, Jane Wyman, only his eldest daughter, Maureen, attended tonight's event. But Reagan's sons by both marriages, Michael and Ron, attended a private birthday celebration for him last Friday at Chasen's in Los Angeles, Reagan's favorite restaurant.

Patti Davis, the daughter of Ronald and Nancy Reagan, is estranged from the family and did not attend either celebration.