Why do managers resist change? While this question has incited a lot of curiosity among researchers in the field of strategic management, it remains inconclusive. Therefore, I analyze the evolution of mental models or ‘dominant logic' in order to reveal insights about the difference in the constitution of mental models. Based on the original definition of ‘dominant logic' as "knowledge structure (of a firm's business strategy)" (Prahalad and Bettis, 1986), a knowledge-based view of the firm (Nonaka, 1994; Grant, 1996; Spender, 1996; Von Krogh and Grand, 2000) is adopted. In addition, this research relies on insights from cognitive social psychology (e.g. Ginsberg, 1990) and evolutionary theory (Nelson and Winter, 1982, Dosi and Nelson, 1994) in order to elicit patterns in the evolution of managers' mental models in six software ventures, divided into 3 age groups according to a central hypothesis on strategic inertia in three age categories.