I needed to throw out the Chinese chewing gum that had kept me preoccupied during our drive through Pyongyang. After only seven minutes, it had lost its flavor, and was at this point giving my jaw an unnecessary workout.

Back home in the States, I would not have given any thought to just spit it out where I stood, to add another point to the constellation of black spots that ubiquitously dot our city streets. But not here in North Korea, where the country makes up for its lack of modern amenities and services with strict social norms of order and cleanliness.

I walked towards a nearby public trashbin, but was stopped by what I found. There was a wet and dirtied – though in otherwise serviceable condition – bill in the ashtray. 5 DPRK Won.

I quickly pulled out my iPhone and tapped on my currency converter. It amounted to roughly $.03 dollars – just enough for a single ride on the Pyongyang metro.

An elderly North Korean man stumbled by, curious to see what had gripped my attention. He followed my gaze to the folded bill now next to my discarded piece of gum.

His eyes dimmed. He shook his head in that way fathers do when young children have made a mistake.

“Just because it isn’t worth much doesn’t mean you should throw it away,” he muttered in Korean.