This chapter turns to the motivation to exert self-control. There is a crucial difference between being unable and being unwilling to exercise self-control. It is a grave mistake to confound the two, as many psychologists and behavioral economists do. In this chapter, I argue that the motivation to exert self-control derives from one’s overall time orientation: One’s general propensity to be moved and motivated by either immediate or future rewards (as indexed by one’s “delay discounting rate”). I show how differences in time orientation are correlated with differences in working memory capacity, and discuss two recent bodies of research that are particularly relevant: the psychology of “mental time travel” and “life history theory.” The conclusion is that people who grow up in harsh and unpredictable circumstances are more likely to develop a present-oriented personality, and thus tend to be less motivated to exert self-control.