Take it from N. Joseph Woodland, a brilliant inventor who passed away last week at the age of 91: Sometimes, a stroke of genius takes nothing more than a stroke of your hand through the sand.

N. Joseph Woodland may not be a household name, but there are likely hundreds, if not thousands, of his famous invention in your household. It’s the barcode, that tiny rectangular grouping of lines that encodes all the products you buy, from a green apple to an Apple iPad. Here’s how the Boy Scouts, an unexpected college visit, a paranoid father, and a little time at the beach turned into one of the century’s most important inventions.

A graduate student at Drexel University in the 1940s, Woodland was already pursuing another invention, his system for delivering elevator music. But when a supermarket executive visited the university to inquire about a system for encoding product data, Woodland was fascinated. And it helped that Woodland’s father had recently forbade him from pursuing his elevator music system, convinced that elevator music was controlled by the Mafia. With that invention on the back-burner, Woodland became consumed with developing a product encoding system. He enlisted classmate Bernard Silver to help him.

As a Boy Scout, Woodland had learned the Morse Code, which inspired him to create a graphical version of the dot-and-dash system. Completely absorbed by the idea, Woodland quit school to devote all his energy to it. He went to live with his grandparents in Miami Beach, and the rest is history. His aha! moment went something like this:

“What I’m going to tell you sounds like a fairy tale,” Mr. Woodland said in 1999. “I poked my four fingers into the sand and for whatever reason — I didn’t know — I pulled my hand toward me and drew four lines. I said: ‘Golly! Now I have four lines, and they could be wide lines and narrow lines instead of dots and dashes.’ ”

From there, he developed and patented a circular version of the barcode. In the 1970s, the circular Woodland-Silver model became the basis for the rectangular barcode that is scanned billions of times each day in supermarkets, retail stores, libraries and beyond.

And the fact that it all started with a little motivation and a few lines in the sand proves that creativity can come in the moments, and places, where we least expect it.

For more on Woodland, read his New York Times obituary.