This paper theorises that a person’s mindset is a commonplace trait that has an impact in economic systems. A mindset contrasts with other theoretics which use choice and information sets to limit the economic actor’s decision-making by focusing on the description of a person’s knowledge rather than on available options. The persistent way a person thinks about the world influences their treatment of information and further development of knowledge. The mindset concept accommodates the complexity of individuals and their idiosyncrasies, whereas a standard economic approach simplifies these characteristics. In this paper, Lamberton’s discussion of mindsets is extended from information sharing, cultural embeddedness and lock-in to the necessity of a mindset held by each person, change in a person’s knowledge and the impact on groups of people. Instead of being a statement about the limited capacity of a person to think, a mindset is a consequence of history and the build-up of knowledge through disjointed experiences. It is argued that a mindset does not necessarily restrict a person to set economic activity, but instead preserves wider economic structures. Through some examples of mindsets, such as the entrepreneurial mindset, this discussion moves away from the acquire-then-use understanding of how people use information towards an economic person with a mind sense constructed through situated learning.