Remembering the past can shape current emotions and behaviors as well as bias anticipations of the future. This awareness that mental states and emotions cohere across time—sometimes called mental time travel—is a fundamental component of social cognition critical for assessing risk, making decisions, and understanding others. In this article, I highlight early competencies and development in young children's reasoning about connections among life history, mind, and emotion. I focus primarily on children's knowledge about emotions and decisions caused by being reminded about the past and thinking about the future. Findings reveal surprising insights in children as young as 3–4 years of age, age‐related changes through middle childhood into adulthood, and individual differences that have implications for mental health.