Among the formal physics textbooks, problem manuals and general expository books lies the domain of non-formal physics—the world of content-specific strategies and styles of reasoning that practising physicists employ but do not fully articulate in print. How and Why in Basic Mechanics tries to capture some elements of this world through the medium of a teacher–student dialogue which runs through the many conceptual barriers that most students and teachers face in different topics of physics, and offers helpful points, clarifications and insights.