What makes the brain such an incredible tool is not just the sheer volume of information it contains but the ease and efficiency with which it can find that information. It used the greatest random-access indexing system ever invented - one that computer scientists haven’t come even close to replicating. Whereas an index in the back of a book provides a single address - a page number - for each important subject, each subject in the brain has hundreds if not thousands of addresses. Our internal memories are associational, nonlinear. You don’t need to know where a particular memory is stored in order to find it. It simply turns up - or doesn’t - when you need it. Because of the dense network that interconnects our memories, we can skip around from memory to memory and idea to idea very rapidly. From Barry White to the color white to milk to the Milky Way is a long voyage conceptually, but a short jaunt neurologically.