‘WE ALL have the same dreams,” wrote the perspicacious Joan Didion.

NOT LONG ago Brooke Hayward and Peter Duchin were described as “a perfect blend of Broadway, Hollywood and New York society . . . possessing those three glamorous worlds.”

Destiny’s tots, as Noel Coward would have called them, both inherited fame and individual talent. They have been wed for 23 years, cohabiting together for 27. She was born the daughter of film star Margaret Sullavan and famous agent-producer Leland Hayward, and she is also a stepsister to Peter and Jane Fonda, as well as to Manhattan decorator Kitty Hawks.

He is the bandleader/musician/suspense writer well-known to almost anybody who ventures onto a dance floor in New York, the Hamptons or Palm Beach. He was born to the famous American bandleader Eddy Duchin and society beauty Marjorie Oelrichs. When his celebrated parents died young, Peter was raised by New York Gov. Averell Harriman and his wife, Marie. In later life he suffered the unwelcome neglect of his famous stepmother, Pamela Churchill Harriman.

Now, the Duchins, who boast an NYC apartment and a country house in New Preston, Conn., are separating. They are already trying out living apart and liking/hating it. One of them is in Manhattan, the other in the country. Their friends are agog. She is a talented writer; he a talented musician. Their homes have been meccas of good food, good company, much happiness. New York social life couldn’t do without either of them.

Peter, who will be giving the downbeat at Cipriani 42nd Street when we present the “Living Landmarks” this year, swears to me there is no one else involved in his wish to be single. “I am 71 years old, and I want to live on my own. I love Brooke very much; she is wonderful. I haven’t a single bad word to say. I suggested we separate, but I had been contemplating doing it for sometime. We don’t want the same things. Believe me, I swear to you there is no ‘other woman,’ no matter what you hear.”

Speaking with Brooke, she didn’t say “Harrumph!” to this; but opined: “I was shocked when he said he wanted to separate. I was flabbergasted. I was literally the last to know.”

Now maybe she’ll write that next fabulous book of which we all know she’s capable. And Peter will keep giving the downbeat. Love them both, wish them the best.

JONATHAN VAN Meter is putting together a story for New York maga zine’s 40th anniversary, so he asked to take me to Michael’s popular watering spot to see if I still “had the power” he imagines I had back when he put me on the cover of 7 Days in 1990. Despite my protest that there’s no such thing as journalism power anymore, I suppose I lucked out.

Here are a few who came by our table as we ordered hamburgers. CBS titan Les Moonves, wearing a fabulous yellow tie, IAC chief Barry Diller, the controversial powerhouse Michael Ovitz, the Shubert theater king Gerald Schoenfeld, p.r. ace Peggy Siegal, true B’way drama queen Kathleen Turner, TV’s Felicia Taylor, producer Terry Allen Kramer, philanthropist Beth deWoody, the Social Diarist David Patrick Columbia, journalism historian Harry Evans, Andrew Lloyd Webber‘s voice in the US Peter Brown. And writer-dramatist Michael Kramer plus entrepreneur Jerry Della Femina, who waved as they exited.

TE LEGEND Clay Felker will be cele brated by his wife, Gail Sheehy, and New York magazine on Sept. 22 at Ethical Culture, 6 to 8. David Frost hosts, and speakers are to be Tom Wolfe, Judy Collins, Gloria Steinem, Maura Sheehy, Richard Reeves, Lesley Stahl and Michael Kramer, with intros by editor Adam Moss. A jazz band will play. The public is invited.

I’S ALIVE! It’s starting, yes, the social season for fall even though the last day of summer is yet to happen. Tomorrow, 7 to 9, Le Cirque will host a kickoff for the coming Fete de Swifty to benefit the Mayor’s Fund. (The actual Fete takes place Sept. 18 at Lex and 73rd in a big tent where Mayor Bloomberg will accept congrats for all he is doing to combat domestic violence.) . . . On Tuesday, the best-dressed list will celebrate its 69th birthday at a Vanity Fair lunch in La Grenouille, and that evening Barry Diller, Diane von Furstenberg, Wendi and Rupert Murdoch invite the cognoscenti to a 23andMe Spit Party at the IAC Building. (I have to go to find out what this means!) . . . The same night, Barnard College will offer Martha Nelson and Anna Quindlen, hosting a cocktail event for new Barnard prexy, Debora L. Spar, at the Time-Life Building . . . Friday the 12th, “Bob Schieffer‘s America,” the book itself, bows in a party at Hill Country where they say to dress “Cowboy Casual.” (That means no spurs.)

I’M HAPPY to report that the great Shakespearean teacher-writer Harold Bloom has recovered from adversity and will be back teaching at Yale this fall . . . THE valuable Rodgers & Hammerstein music catalog is going up for sale, and it’s big showbiz news. We told you this on Aug. 3.