This chapter explores the multifaceted nature of inflation and its profound implications for investors. It examines the historical evolution of inflation across major economies—particularly the United States and China—highlighting how monetary policies, wars, and structural transformations have shaped inflationary trends over the past century. The chapter analyzes how inflation erodes purchasing power, affects asset valuations, and influences portfolio performance, emphasizing the distinction between nominal and real investment returns. By tracing key inflationary episodes and policy responses, it provides a comprehensive understanding of how inflation interacts with macroeconomic conditions and financial markets.