This chapter shows that the human information problem poses a fundamental challenge for decision-making even in simple consumption decisions. The incompleteness of information and the costs of obtaining information lead to the use of concepts such as bounded rationality and sequential information search. The concept of “match value” of preferences and product attributes for differentiated goods allows a formal analysis of the effect of missing product information on consumption decisions. We start with the idealized reference case of perfect information. However, if the information is incomplete, individuals learn through Bayesian Learning. Since this learning process is central to the formation of a concept of reality, the second part of the chapter provides an insight into the dynamic emergence of such conceptions of reality (Bayesian Beliefs) through information intake, for both binary and continuous variables. These insights provide the basis for understanding how ideologies can serve as cognitive aids in more complex decision-making situations to overcome the information problem.