As with any data, a code must exist otherwise it cannot be downloaded or loaded later; furthermore, sensory signals (signals) are needed to successfully perform Google search, whether it is from a human (brain) or a man-made computer. When the brain attempts to retrieve a memory that has already been stored, (a) the retrieval may be intentional when we intentionally try to remember something (e.g., exam materials) or (b) unintentional when triggered by a stimulus that corresponds to something pertinent to the memory (e.g., Confessions of an Egg Hater, p. 177). Understanding this helps with recall; therefore, it is essential for good study