Celebrated science communicator Carl Sagan had a way of speaking and writing that instilled listeners and readers with wonder and nurtured the human drive to explore. It was partially for this reason that the Cornell University scientist and narrator of the timeless PBS documentary Cosmos was often invited into schools to guest-teach kids of all ages.

In his book, The Demon-Haunted World, Sagan shared how regularly impressed he was with kindergartners and first-graders. “Many of these children are natural-born scientists — although heavy on the wonder side and light on the skepticism. They’re curious, intellectually vigorous. Provocative and insightful questions bubble out of them.

We lose our wonder

But at the same time, Sagan noted a disconcerting transformation that consistently occurs by the time kids grow to become seniors in high school:

“They memorize ‘facts.’ By and large, though, the joy of discovery, the life behind those facts, has gone out of them. They’ve lost much of the wonder and gained very little skepticism. They’re worried about asking ‘dumb’ questions; they’re willing to accept inadequate answers…”

Sagan speculated on why this invariably happens. “I’d guess that it’s partially peer pressure not to excel; partly that society teaches short-term gratification; partly the impression that science or mathematics won’t buy you a sports car; partly that so little is expected of students…” he wrote.

Are adults to blame?

But, according to Sagan, those myriad factors all pale in comparison to a more pernicious reason: the indifference of adults when confronted with a young child’s effervescent wonder.

“Too many teachers and parents answer with irritation or ridicule, or quickly move on to something else… Children soon recognize that somehow this kind of question annoys the grown-ups. A few more experiences like it, and another child has been lost to science,” Sagan wrote.

What would be a better way to handle kids’ frequent bursts of inquisitiveness? The obvious response, Sagan said, is simply to try to answer their queries. “Even an incomplete attempt constitutes a reassurance and encouragement,” he noted.

If you truly have no idea where to begin when a child forces you to grapple with why the grass is green or how the Earth formed, you can look it up on your phone and translate the facts as best you can. Better yet, you could voyage to the local library or, if possible, run an experiment that addresses their query. And if their question doesn’t yet have a satisfactory answer? Sagan suggested a reply for this scenario as well.

“Maybe when you grow up, you’ll be the first to find out.”

Perhaps one essential way that humanity advances is through turnover. As generations of people pass, others grow to take their place, bringing novel questions, fresh ideas, vibrant energy, and often a burning drive to change the world for the better. In this model, there may be nothing more precious than an adolescent filled with wonder. Affirming kids’ fundamental urge to explore is fertilizer for their brains.

“Bright, curious children are a national and world resource,” Sagan wrote. “They need to be cared for, cherished, and encouraged.”

This article was first published at Big Think.