It is often said that we are nothing but the sum of our experiences. The accumulation of past experiences matters for economic behavior in any given moment: They can shape the objectives and goals we set, the perceived constraints around choices to be made, and they help form our attitudes and views of the world around us. A fast-growing literature in economics studies such experience effects, drawing together work in sociology, social psychology, and neuroscience, to understand how past experiences sink into memory, are recalled when making decisions, and compete with other relevant sources of information we might have, to shape consequential behaviors throughout life.