One of the highlights of my childhood was my visit to the 1964–65 New York World’s Fair. There was the Sinclair exhibit with its life-size dinosaurs, and Ford’s Magic Skyway, where you could watch the entire history of the human race go by from the comfort of a self-driving Mustang convertible. There was the Illinois pavilion, where Disney’s audio-animatronic Abraham Lincoln miraculously stood up and gave a speech, and the IBM pavilion, where the audience was hydraulically lifted into a giant egg and dazzled by an immersive multimedia show.  There was DuPont’s “Wonderful World of Chemistry,” in which live actors sang, danced, and interacted with filmed actors projected onto moving screens. And there were technological innovations that I’d never seen before: color TV, “Touch-Tone” phones with buttons instead of dials, and IBM Selectric typewriters, where the type element moved along a track while the carriage stood still.

As I got older, my wondrous memories of that fair led me to be interested in another exposition that once had been held on the same site: the 1939-40 World’s Fair. Unlike the later fair, which was a hodgepodge of futuristic architectural styles, the 1939 fair was a visual delight, featuring Art Deco graphics and clean Modernist architecture. It had an overarching theme — “The World of Tomorrow” — intended to lift the spirits of a population that had weathered the Great Depression and was looking ahead to a better and more prosperous world. Its most famous exhibit was General Motors’ Futurama, which displayed an imagined model city of 1960, with gleaming suburbs connected by a network of fast, efficient highways (a new idea at the time). I’ve watched films taken at the fair and seen exhibits of its relics, but I’ve always wished I could have experienced it in person.

One reason for my emotional attachment to that fair was that my mother had been there. I remembered her stories about the majestic size of the fair’s centerpiece, the Trylon and Perisphere; about seeing television for the first time; about being introduced to nylon stockings; and about trying out a new type of pen, the ballpoint, which didn’t have to be dipped in ink. Compared to those things, push-button phones and improved typewriters felt trivial.

A few years before her death, I told my mother about how I’d been influenced by her descriptions of the 1939 fair when I was growing up. I expected her to lapse into warm reminiscences, but instead she looked at me like I was crazy.

“What are you talking about?” she said. “I never went to that fair. I was five years old! Even if I had gone, I wouldn’t have paid attention to things like pens and nylon stockings.”

I quickly did the math, and was stunned to realize that she was indeed five years old in 1939. Evidently, she had never told the stories that I so clearly remembered her telling. I still have no idea where those false memories came from.

That conversation left me shaken. What other memories, what other explanatory stories, were pure inventions? So much of my sense of who I am comes from remembered events and conversations. How can I be sure that any of them are real?

The answer is that I can’t — especially now that all of the members of my immediate family are gone. Other than me, there are no surviving witnesses to my childhood. There is no objective reality about my formative years; there is only what’s in my head. The stories that form the basis for much of what I’ve written in my blog posts may be entirely fictional.

My only consolation is that if they are fiction, they’re pretty good fiction. I don’t think I have the skill to have made them up consciously. Perhaps I’m not a product of my past; I’m just a product of what my current brain thinks was my past. If so, that doesn’t stop me from drawing lessons from it.

Still, who would have thought that The World of Yesterday was as much a product of imagination as The World of Tomorrow?