This chapter examines the various differences and gaps (DaGs) that emerge from human interactions, analysing them at both macro and micro levels. It begins by exploring how System 1 (fast, emotional) and System 2 (slow, rational) thinking contribute to longitudinal and cross-sectional variabilities in human performance. At the macro-level, the chapter introduces a framework demonstrating how material, cognitive, and affective energies interact with environmental demands to generate DaGs, while exploring how proper external support can influence these energy states. At the micro-level, the chapter presents a theoretical model mapping internal processes and DaGs within individuals, incorporating elements from established information processing and situation awareness models. This model identifies five key criteria—filtering, trust, intervention, suitability, and optimisation—that influence how individuals process information and respond to situations. The chapter emphasises the non-deterministic nature of human performance and the challenges in measuring and predicting DaGs, while acknowledging their essential role in activating energy and driving professional development.