This book presents a clear and readable description of one of the most mysterious concepts of physics: Entropy. It contains a self-learning kit that guides the reader in understanding the concepts of entropy. In the first part, the reader is asked to play the familiar twenty-Question game. Once the reader feels comfortable with playing this game and acquires proficiency in playing the game effectively (intelligently), he or she will be able to capture the elusive and used-to-be mysterious concept of entropy. There will be no more speculative or arbitrary interpretations, nor “older” or “modern” views of entropy. This book will guide readers in choosing their own interpretation of entropy.