I’ve never been to Universal Studios, so when I saw a Seattle billboard that proclaimed, Bruce the Musical, I thought I was the only resident who would understand the reference.

I was 13 years old in the summer of 1974 when Jaws was being filmed on the Vineyard. The mechanical shark was named Bruce. I’m not sure if the movie even had a name yet that summer. For many of us, it mostly meant chasing excitement on our bicycles, and hearing rumors of what others were being paid as “real” extras. My Indiana cousins came to visit. My cool aunt bought jeans that she anchored to a rock and floated at State Beach, even though I can’t remember why.

With my teenage writing students in Seattle I use the prompt, “What we didn’t know . . .” Could there be a more fitting prompt, not just for Jaws, but for Island history? What we didn’t know was that the Vineyard would become even more connected with Kennedy tragedies. That John Belushi would put a Chilmark cemetery on the map? That the movie being filmed that summer would become a one-word phenomenon that, unlike the first mechanical shark, would never die?

Of course, 50 years later, you realize that at age 13 what you didn’t know was exponential. Think of it: no cell phones, no Internet, no Islanders Talk on Facebook. Just the ability to catch multiple rings at the Flying Horses while sensing you’re almost too old to be riding the carousel.

We can all play this game and there are collective moments, too. We didn’t know on that Tuesday morning in 2001, hearing fighter jets from Otis Air Force Base, that there was a before and after line that would never be erased by the tide. We didn’t know that we would wake to the news that John Kennedy Jr.’s plane was missing off Aquinnah, but remembered hearing fog horns. We didn’t know that an Illinois senator would become President and have a daughter who worked at Nancy’s.

And we didn’t know that we would never forget every detail of the Jaws film shoot, even the faux cabanas on State Beach and the barge we could see off in the distance.

I also didn’t know that 50 years later I would spend so much time looking out on the Vineyard Haven harbor and watching the Alabama’s sunset cruise from my father’s perfectly-situated hospital room, in a hospital I could never have envisioned.

But I did know, on the day that I saw the Bruce the Musical sign, that the billboard was meant for me, and I needed to see the show before flying east to the Vineyard.

I bought one ticket and upon entering the Seattle Rep a friend who is a season ticket holder waved me over.

“This is my summer,” I told her.

I don’t know if the musical will make it to Broadway, or if there’s a single song that I will recognize a year later. But it was so cleverly staged, and a rollercoaster of getting local references right, and then botching accents.

“You should come to the green room after the play,” my friend said. “The actors will want to hear from you.”

But there was nothing I could really share, other than I was 13 years old in 1974, and the movie being made on the Island was its own excitement. It’s what we didn’t know that is most intriguing. Unlike hurricanes, those that hit and those that don’t, the storm that was Jaws has shaped Island history. We all have that summer.

In truth, every day is an exercise in what we didn’t know when we got out of bed. And there is also what we do know, and have always known. For me, it is that under my Oak Bluffs cottage eaves on a rainy day will always be the place I am the most content. It is where I am most likely to connect with my own muse, although mine will never be named Bruce.

Peggy Sturdivant lives in Oak Bluffs and Seattle, Wash.