Apple had a mouse problem.

Steve Jobs and his team were getting ready to bring Apple's first personal computer to market, but one critical component was far from complete. All iterations of the mouse design were expensive, unreliable, and difficult to produce.

So in 1980, Apple to turned to IDEO, a design firm founded and led by creative guru David Kelly. The ask? Design a usable mouse that would last while slashing production costs by 10 percent.

Kelly and his design team pulled together household items to design a working prototype. They shopped their medicine cabinets. They grabbed stuff out of their refrigerators.

A roll-on deodorant ball served as the mouse ball. A yellow butter dish cover served as the top. "The resulting mouse proved mechanically and economically sound and was changed only slightly when adapted for use with the first Macintosh computer," IDEO says.

After designing the Apple mouse, Kelly went on to launch Stanford's and become the bestselling co-author of Creative Confidence. His TED Talk on the topic has over five million views. Today, IDEO is one of the most successful design and innovation firms on the planet. If you've ever heard the term "design thinking," you have David Kelly to thank.

Almost 40 years later, Kelly still has that very first Apple mouse in his office. You probably would too, if you had designed the first Apple mouse. But that's not all Kelly has displayed on his office shelves.

Kelly's office walls are lined with cubbies, each chockfull of a random-seeming assortment of stuff. Model cars. An ancient-looking phone. A shoe. A giant wrench. A black-and-white wedding photograph. And lots more stuff whose existence appears to have no rhyme or reason.

This clutter of stuff makes minimalists queasy. But for Kelly, it's vital to his creative process. "This kind of clutter of memories is emotional," Kelly says in this video tour of his office, recently released by IDEO.

Kelly surrounds himself with significant items from different periods of his life, each of which represent a different memory and emotion.

"All these things have meaning," Kelly goes onto explain,"but they're not precious. I want to have lots of memories, lots of emotions. If you have one thing that's really special and you put it in the center, that's one emotion."

He says he gets it from his mom, who used to "shop the basement." For his birthday, she might send him an old childhood toy or his boy scout uniform. "I'm kind of in that same vein as my mother," Kelly says. "I'm keeping things that are meaningful."