Why should I start investing early?

Starting early maximizes the power of compound interest — your earnings generate their own earnings over time. A 25-year-old who invests $5,000/year for 10 years and stops will have more at age 65 than a 35-year-old who invests $5,000/year for 30 years. Time in the market is the most powerful variable available to young investors, and it cannot be bought back later.