The purpose of this paper is twofold: first, it analyses the relationship between optimism about the emergence of future entrepreneurial opportunities and the length of the entrepreneurial experience; second, it aims to identify the external factors that can moderate this relationship. Our empirical analysis is conducted on a cross-national sample of 450,000 individuals drawn from the Adult Population Survey (APS), which is collected by the Global Entrepreneurship Monitor (GEM) consortium and covers the period from 2009 to 2011. Our results find an inverted U-shaped relationship between the length of the entrepreneurial experience and our indicator of optimism. Additionally, the relationship between optimism and length of entrepreneurial experience is conditioned by a set of external-factor moderators, such as social capital and the individuals' perception of how valued entrepreneurship is as a career choice in their country.