This reflective essay focuses on critically reviewing different theories and evaluating practical applications of theoretical underpinnings while understanding personal strengths and weaknesses and generating a plan for self-development. The essay covers key concepts and theories such as Johari Window, Self Efficacy Theory, Decision Making Concepts, Game Theory, Critical Thinking Framework, Critical Thinking Tools, Deductive versus Inductive Reasoning/Arguments, and Triangular Thinking. The author reflects on the impact of these concepts on personal decision making and future development.