I love natural history museums—especially dinosaur exhibits. The one in my hometown played such an integral role in my educational development as a child it’s a genuine curiosity I didn’t grow up to be a paleontologist. Dinosaur names like Parasaurolophus and Deinonychus rolled off my tongue before I had any idea what a multiplication table was. I’ve maintained a membership since moving back to California, and visit frequently; it’s one of those few places that both stimulates my imagination and grants me a measure of peace. I feel at most myself among the bones of the ancient dead.

It’s where I recently met famed paleontologist Jack Horner, one of my childhood heroes, who was giving a lecture as promotion for his new book. Inside my copy he wrote, “The bones tell us stories. We just have to how learn to read them.”

The museum has expanded and grown magnificently in the last decade, but if I close my eyes I can follow my boyhood steps through the facility of my youth, wandering from the whale skeleton mounted over the front entrance through the displays of southwestern mammals and marine life downstairs, before finally reaching the main dinosaur display, where a complete Allosaurus skeleton towers over me from the centerpiece. I can see every vertebra in the tail, every chasm in the skull, every curving tooth and claw.

These “thunder lizards” should terrify me, but they don’t. Terror is nothing but wonder without the awe. And there is awe aplenty for me inside this building.

A few years ago I participated in a neurological study and learned that I possess what the researchers defined as a “low-grade eidetic memory,” or what is commonly referred to as a photographic memory. Eidetic individuals are known for their extremely accurate recall when it comes to visual images, memories summoned up like still images or filmstrips.

This explains why I was able to describe the geographic orientation of the furniture in my best friend’s new house after five minutes spent walking through it for the first time; why I never got lost exploring town on my bike as teenager, even though I’m terrible at memorizing street placement; why I can remember, in uncomfortable detail, what every girl I’ve gone out with wore on our first date—and what they looked like in later, less-dressed states.

Why I can’t seem to forget dozens of sights from my experiences in Hurricane Katrina that would best be left unremembered.

The term photographic memory is a flawed one though, I think. The word “photograph” implies someone making a conscious decision to capture and preserve those images, and that’s not how the human mind—or at least not mine—works. I’m not speaking of the basic mnemonic devices of memorization, but rather the active choice that this image, this particular set of visual information will be stored. While there’s a fair amount of coherence among things from, say, my preteen years forward, anything beyond that is really just a meaningless shuffle of disordered images, odd fragments of things remembered but not necessarily known.

These memories are not photographs; they are fossils, their bones extruding from the sedimentary rock of the mind. And like true fossils, some of them have to be studied closely before their stories reveal themselves.

One in particular has surfaced recently, provoked in part by recent tour I took through the museum’s off-exhibit areas during Horner’s presentation. It’s an old one; Triassic period, if we wanted to stretch the metaphor a bit further. In it I’m very young, five or six at the oldest, attending one of the museum’s weeklong parent/child classes, where we’re learning about paleontology by building paper-mache models of prehistoric creatures. A half-formed Pteranodon, one of the largest of the non-dinosaur flying pterosaurs, sits on the plastic painter’s tarp in front of my mother and me, a wet coat of chalky gray paint just applied to its newspaper skin.

Sharing the workspace and craft supplies with us are G., my mother’s partner in adultery and the man who would become my stepfather, and his daughter, my eventual stepsister. They’re building a generic long-necked sauropod dinosaur. This is the first time I’ve met them.

This isn’t some sort of revelation or epiphany; the extraction of this memory doesn’t send cathartic earthquakes rumbling through my psyche or sully my love of the museum. This class was one of a dozen or so I attended at the various scientific institutes around town over the years, and the memory of it has always been there to some degree of clarity or another. But it’s only now, when I look at it in the light of adulthood, that I understand it.

And what I understand is that those two cheaters were on an extended date. Enrolling us children in this class allowed them the opportunity to spend the week together, hiding in plain sight under the noses of their spouses. While my would-be stepsister and I were learning how to reconstruct prehistoric life, our parents were in engaging in behavior that would destroy our present ones.

It isn’t a happy memory, for certain, but neither is it a sad one. Ultimately it’s more of a curiosity, another roll-your-eyes tale of how some parents will use their children to leverage their own happiness. But out of this I got a nifty model and a lifelong fascination with the natural sciences; all they got was a couple of divorces and a legacy of pain given and received. Fair to say I came out on the winning end of that deal.

My Pteranodon was an ungainly thing, ready to take wing but far, far too heavy in the torso for any creature hoping to take flight. I loved it. It occupied a place on honor on my bedside shelf for years. I’ve no idea what’s become of it. It’s possible, I suppose, that it’s in a box somewhere, locked up in storage with my few remaining childhood things. More likely it’s succumbed to the ravages of time, the paint and paper of its body crumbled to dust, existing now only as another fossilized fragment of memory.