" Thinking about the word “coffee” makes you think about the color black and also about breakfast and the taste of bitterness, that’s a function of a cascade of electrical impulses rocketing around a real physical pathway inside your brain, which links a set of neurons that encode the concept of coffee with others containing the concepts of blackness, breakfast, and bitterness. That much scientists know. But how exactly a collection of cells could “contain” a memory remains among the deepest conundrums of neuroscience. "

― Joshua Foer , Moonwalking with Einstein: The Art and Science of Remembering Everything