Psychology is the study of the brain, mind, and behavior. One psychological metaphor couches humans as information processors. Whether or not this is the most accurate way to represent the brain/mind, it provides a useful framework. Information processing begins when external stimuli reach the sense organs. We use both bottom up processing, constructing meaning out of basic units, and top down processing, relying on our preexisting knowledge to shape experiences. Once information is transduced, perceived, and manipulated in our working memory, we can form a decision or action plan to produce behavior.
Information accessibility determines what information is used. Accessibility can mean many things, such as ease of retrieval, availability (i.e., availability heuristic), representativeness (i.e., representativeness heuristic), automaticity, etc… The more readily info is constructed/reconstructed, the more likely it will be used. Therefore, our current mindset can affect our later mindset. For example, some research suggests that more abstract mindsets at one point in time can lead to a more purpose-oriented (opposed to process-oriented) mode of thinking later on.
Also, thinking isn’t constrained to the here-and-now. Rather, we frequently time travel into the future or meander toward the past using our mind. Therefore, our mindset can have dramatic consequences on downstream outcomes.