WORLD'S FAIRS gave us the Eiffel Tower and the Space Needle, the Ford Mustang and the Ferris Wheel, Sally Rand's fan dance, steak sauce and giant steam engines. They gave us a reason to celebrate the present and look forward to the future. And they gave us memories.

Our personal memories of world's fairs are as much a snapshot of a certain time in our lives as they are specific recollections of the exhibits we saw. For a lot of us, a world's fair was also a rite of passage - our first trip to a major city, a honeymoon, the first vacation we took on our own. Whether our memories are entirely accurate or not probably doesn't even matter. What does matter is that we have them, and thus we share a common denominator with the rest of our generation.

Historians look back on world's fairs and judge them within a larger context, deciding which ones were important and which ones were not. We ordinary folks use a simpler standard. For most of us, the best world's fair ever held will always be the first one we attended. For my brother and I, that means the fair that opened at Flushing Meadow during April school vacation in 1964, when he was twelve and I was fourteen.

From our first sighting of the Unisphere through the windshield of the family Mercury as we trundled along the Van Wyck Expressway, it was clear that this time our parents had chosen a vacation with potential. Spreading before us was a dazzling panorama of promise and possibility unlike anything we had ever seen. Everything was modern and magical and larger than life. Pavilions soared skyward in strange futuristic shapes. Pop Art was everywhere - a ten-story rocket, an eighty-foot car, a giant rubber tire turned into a ferris wheel.

It was all incredible and it was all ours. For two whole days, armed with piggybank proceeds and official guide books, we were on our own to travel wherever curiosity carried us - through an amazing world of color and space exploration and exotic foreign lands.

We stuck our heads into plastic spheres at Clairol to see how we'd look in Jackie Kennedy bouffants or frosted flips, played with IBM Selectrics at the Typewriter Bar, and with touch-tone phones at the Bell Pavilion. At Parker Pen we filled out questionnaires and were matched - by computer! - with pen pals. At DuPont, actors in go-go boots, Oleg Cassini outfits and hats trimmed in giant molecules sang and danced and introduced us to dripless paint and the Happy Plastics Family.

We took pictures on the lunar landscape roof at Eastman Kodak, sampled peanut soup in the tree house restaurant at the African pavilion, and waited in a long, boring line to ride a moving sidewalk past Michelangelo's Pieta. And we ate as many Bel-Gem waffles as funds and fortitude allowed.

At General Motors' Futurama we were transported to a time when tourists would board atomic submarine trains for jaunts under the ice of Antarctica or drive their Aqua-Scooters to undersea hotels. Heady stuff for two kids within spitting distance of their first drivers' licenses.

We walked from Albany to Buffalo on the giant map at the New York State pavilion and argued about how we'd spend the million dollars on the money tree at American Express. At Festival of Gas we fantasized about the Norge Dishmaker ending our nightly dishwashing duties forever - by turning dirty plastic dinner dishes into brand new plates in time for breakfast.

And who could ever forget that epitome of fallout shelters, the Underground Home? A subterranean ranch house that promised us freedom from pollution and radiation, it boasted a glamorous round bed, backlit mural "landscaping" and a patio complete with chaise lounges and a barbecue grill.

Since we had spent weeks during the Cuban missile crisis diving under our school desks in practice air raid drills, the idea of living underground didn't seem all that far-fetched (or entirely undesirable, to my shallow fourteen year-old mind, especially if a round bed was part of the deal).

Like most Americans in 1964, we were fascinated with space. We had grown up with Sputnik and watched, in breathless amazement on a classroom TV as Alan Shepard took his fifteen-minute Mercury flight in 1961. Our vocabularies were filled with words like Telstar and splashdown, and NASA was becoming as familiar as The Ed Sullivan Show. We drank Tang, wondered how astronauts went to the bathroom, and tried to imagine life at zero gravity. The world's fair was a spectacular showcase of this new era, a cornucopia of command modules and booster rockets, space stations and moon domes - and it gave us our first ever opportunity to see it all up close.

Of all the innovations on display, though, our hands-down favorite was Audio-Animatronics, a Walt Disney-designed invention that produced incredibly life-like electronic figures who seemed to move and speak just like real people. Several pavilions used them, but the best, as far as we were concerned, was the G.E. Carousel of Progress.

There, in theater seats that traveled around a center stage, we watched an entire audio-animatronics family move through history, from the days of drudgery before electricity right up to an ultramodern life of leisure in their all-electric home. So mesmerized were we that today, over thirty years later, we can both still hum the exhibit's theme song on command.

For us, THE world's fair will always be 1964. Looking back, it still seems magical - even though the great big beautiful tomorrow of G.E.'s theme song didn't turn out quite as well as predicted. Who knew back then that the Happy Plastics Family would end up worrying about overflowing landfills, school violence and cholesterol?

Personally, I hope they fared better. I like to think they're still out there somewhere, maybe in the Talking Formica House, firing up their Dishmaker and eating lots of Bel-Gem waffles.