This report provides a comprehensive analysis of consumer behaviour, using Harley Davidson's entry into the Indian market as a case study. The report delves into various aspects of consumer behaviour, including personality and self-concept theories, reference groups, perception, motivation, and learning and memory. It explains how these factors influence consumer purchasing decisions, particularly in the context of Harley Davidson motorcycles. The analysis considers the impact of reference groups on consumer choices, the role of perception and motivation in shaping brand preferences, and the influence of learning and memory on consumer behaviour. The conclusion summarizes the key findings, emphasizing the importance of understanding consumer needs and expectations for achieving marketing success, and the role of personality theory in understanding buying behavior. The report references academic sources to support its claims and provide a well-rounded perspective on the topic.