In 1980, I had pimples and braces. The teachers at Kellogg Middle School in Seattle occasionally said something interesting, but mostly the classroom was a banal place that rewarded conformity. There was an ever-present rigidity growing up during the Reagan Era that seemed to bind the soul. 

One evening, something startling happened. I stumbled upon a 13-hour PBS series called Cosmos, and it changed my life. It was written and hosted by a physics professor at Cornell University named Carl Sagan. I was glued.

Cosmos was about the universe--its history, its origins and its destiny. It was about the physical laws that govern reality and how mankind, over thousands of years, slowly began to parse, dissect and comprehend this crazy reality we find ourselves in. Cosmos was about the epic clash between superstition and reason. It was an engrossing exploration of the longing within the human spirit to understand the world and our place in it, using scientific methodology. Sagan made it seem as though the fate of our species lies in the balance.

I remember Sagan showing me factories that were belching pollutants into the sky, bombs falling from planes, the horror of a hydrogen explosion. I heard Sagan's voiceover: "The world is divided politically, but ecologically it is tightly woven. We have uncovered other worlds with choking atmospheres and deadly surfaces. Shall we then re-create these hells on earth? If we ruin the earth, there is no place else to go. There are worlds that began with as much apparent promise as ours, but something went wrong..."

I had no idea the stakes were so high. Cosmos firmly planted in my eighth-grade mind the audacious proposal that education is more than a body of knowledge. It is a lifelong responsibility to each other--and the planet. It is a way of thinking, of skeptically interrogating the universe and ourselves with a delicate understanding of human fallibility. In his own eloquent and original way, Sagan was saying that the human struggle is not to prove the efficacy of our own beliefs, but to be wrenchingly obligated to recognize the way things really are.

The idea that you could learn about the world, record your journey on film, share it with others and thereby contribute to the civic discourse of the country--that for me was a revelation. All of a sudden, Kellogg Middle School seemed like the ancient library in Egypt that Sagan discussed in Episode One: a place to liberate the mind from dogma, bigotry, falsehood and magic.

Last summer, my nine-year-old son Joaquin and I took a journey together. It was a Sunday afternoon and we climbed into the treehouse in our backyard. There, beneath an exquisite canopy of leaves, amid a soft June breeze, we sipped lemonade and watched Cosmos on my laptop. It had been over 30 years since I had seen the show, and I was a bit worried it would be dated and boring. True, the aesthetics were old-fashioned, and the computer graphics, which once seemed so cutting-edge, were now a bit stale. But neither of us was bored. In fact, Joaquin loved it. He couldn't stop talking about how smart Eratosthenes was to figure out, 2,000 years ago, that the world was round, simply by using a couple of sticks in the Egyptian desert. 

Over the weeks that followed, Joaquin and I watched the entire series together. We talked about artificial and natural selection, the size of the universe, the fourth dimension, truth and superstition, civilization and civic responsibility. For me, it all added up to an exquisite reminder of why we do what we do. 

John J. Valadez is a documentary filmmaker living in New York.  His most recent work The Longoria Affair about the birth of the Mexican-American civil rights movement aired on the PBS series Independent Lens and has been nominated for an Emmy.