No matter how frequent you train, running is a constant challenge. Last week, during one particularly sluggish run, I found inspiration to keep pushing myself from an unlikely comrade: an unfamiliar long-boarder approaching me from the opposite direction.

He couldn’t have been older than 15. As he drew nearer, he smiled, and I smiled back. Then, without thinking, I outstretched my right arm to signal a high-five. He did the same.

“Thwack!”

It was one of those good ones—you know, the kind that makes a loud “pop” sound without hurting. He smiled again, only bigger this time. I did the same. Then I picked up my pace to finish strong.

There’s something special that takes place when strangers cheer you on. While the support of family and friends can anchor your success, the unexpected applause by strangers can be a rush of adrenaline—like how a swelling crowd inspires unyielding athletes or a triumphant symphony.

I know that high-five made my day. And I’m sure it did the same for my new skateboarding friend, given the toothy grin he left with. Rock on, humanity!