When I was a teenager, I stumbled upon the fountain of youth.

I went to hear a concert one summer day at the Marlboro Music Festival in Vermont. I must have been fifteen, maybe sixteen. As it happened, the guest conductor that day was the legendary Spanish cellist, Pablo Casals.

At the appointed moment, a hush fell over the audience. Through a door on the far left, by the edge of the stage, an odd trio entered: two young people, a man and a woman both in their twenties, flanking a crinkled, slumped, nearly inanimate shell of a person. It was the maestro. Then in his mid-nineties, he honestly looked on the verge of comatose.

Slowly, ever so slowly, the two edged forward with their charge between them. I could feel the audience almost willing him forward, praying with each shuffling step that he would be able to take another. Gradually, the trio approached the podium.

“And this guy is going to conduct?” I thought. “He can barely see!”

They reached their destination. After setting him into place at the podium, the two assistants silently withdrew. The old man remained in place, motionless, his hands latched onto the podium that was his only visible means of support.

And then an invisible means of support appeared.

All at once, so suddenly that I nearly jumped, his eyes snapped open and both hands flew up into the air where they paused like the twin triggers of two missiles launchers in the moment before ignition. It was as if a great electric current has suddenly shot through his body, or an unseen switch had been thrown.

And then he gave the downbeat, and every musician burst into Mozart at the same instant.

For the next twenty or thirty minutes, the man on the podium hopped and jumped and danced, playing that chamber orchestra as if he were a master puppeteer and they his musical marionettes, and the halls rang with music … until the last note sounded.

The fire left his eyes, his hands settled back down to the podium, and it looked as if all life had left his body. The two assistants reappeared, and they walked the barely shuffling old man off the stage again.

I’d never seen anything like it. I couldn’t stop thinking about it. I still can’t.

Was Casals conducting the music? Or was the music conducting him?

I thought about Casals again today as I was getting ready for a radio interview.

While messing with a few notes on leadership (the interview was about our new release, The Go-Giver Leader), I suddenly had a thought. I started scribbling and then, lo and behold, there on the page was a whole new slant on leadership, an idea I’d never had before.

I say “I suddenly had a thought” — but that isn’t how it felt. The experience of it was more like, suddenly a thought had me.

In the middle of the film American Beauty there is a segment where the teenage boy next door (Wes Bentley) shows a video he made of a plastic bag being caught and carried in the wind, drifting and sailing and swooping this way and that. (Or, like the flying feather the camera follows at the end of Forrest Gump.)

That’s what Casals looked like: a feather being carried in the wind of the music. And that’s how it felt, too, to be carried drifting and sailing and swooping by this new thought. For those moments, as I chased that thought, I felt ageless.

I suspect those moments, every time they happen, lengthen my lifespan. (They certainly deepen it.) Much as conducting did Casals’s.

That’s what I mean by the fountain of youth.

I remember reading, when I was a boy, that conductors tend to have exceptionally long lives. (The author saying this, as I recall, was New York Times music critic Harold Schonberg, in his book The Great Conductors.) Leopold Stokowski, whom you probably saw in the Disney movie Fantasia, conducted in public at ninety-one, and was still recording at ninety-three. In 1956 MetLife Insurance researchers identified 437 symphony and opera conductors. After following them for twenty years, they concluded that conductors live 38 percent longer lives than the rest of us.

Some have concluded that this is simply a matter of cardiovascular exercise. I think there’s more to it than that.

I think that what shot through Casals, reanimating his body long enough to conduct a Mozart symphony, was what Mihaly Csikszentmihalyi famously calls flow. I think that’s the same thing I felt when I was gripped and pulled by that thought.

I see the Casals effect happen in our dog, Ben, who is getting on in years and arthritic in his legs. Normally he walks at a fairly careful, deliberate pace, sometimes with a limp. But when my wife, Ana, returns home from an errand, whether she was gone for hours or just minutes, Ben has the exact same reaction: he hops up and down against her legs and then runs around the house like a puppy, his arthritis forgotten, deliberate pace and posture instantaneously replaced by full-out physical exuberance — a feather carried willy-nilly on winds of pure joy. She’s home! she’s home! she’s home! (Full disclosure: I tend to have pretty much the same reaction, though generally without the hopping and running.)

Ana is Ben’s Mozart, the miraculous thing around which his life revolves, that magical wind that can reanimate him no matter what. Call it joy, call it flow, call it being carried through the air by that thing you are so devoted to that it causes you to forget all about yourself … whatever you want to call it, I think it makes you ageless.

What makes you float aloft in currents of flow?

What is your Mozart?