New York University professor Louise Harpman is a proponent of a sort of mindfulness she calls “visual literacy.” The concept is simple: to notice that every little thing around us has been designed by someone. It’s that idea that might help explain why Harpman keeps over 550 disposable coffee lids under her bed.

Those lids—stored in acid-free boxes—are the largest collection of independently patented coffee lids in the world. Harpman co-owns them with her partner Specht Harpman, and the myriad of lids cover an evolving type of very specific invention. They are constantly updating the collection, which has garnered a lot of attention over the years, from a feature in Cabinet Magazine to an exhibit at the National Museum of American History.

In the video above, Harpman talks about her interest in the plastic coffee lid, both from a design perspective and as the language of America’s on-the-go dining culture. Each lid has its own nuance and (theoretically) innovation, which are all part of a larger story about the history of mobile caffeination.

According to Harpman, “We tried to understand what it was that was driving innovation. What problems are the designers trying to solve? Why isn’t there a best lid? Why don’t we have the equivalent of the paper clip? There’s still always improvements being offered.”