This chapter critically examines two foundational assumptions in classical physiotherapy and sports training: the use of person- and time-independent movement models and the belief that repetition and correction are the main paths to effective learning. Drawing on insights from biomechanics, systems theory, philosophy, and historical learning paradigms, the chapter deconstructs these assumptions by emphasizing the individuality of movement patterns, even from the very beginning of learning. It contrasts weak and strong individuality, discusses how conventional statistical approaches often obscure person-specific variability, and introduces process-oriented, topological analysis as a more accurate method for understanding motor behavior. The limitations of repetition-based learning are explored, with attention to cultural, historical, and neurological contexts. Ultimately, the chapter makes a strong case for embracing nonlinear, individualized learning approaches, challenging long-standing norms in both therapy and training sciences.