What is compound interest, really?
Simple interest pays you on the principal only. Compound interest pays you on the principal plus all the interest you have already earned. The math is exponential, not linear. The catch: it takes years to feel the effect. The first decade looks slow. The fourth decade looks unreal. This is why starting at 25 is worth dramatically more than starting at 35, even if the 35-year-old invests more per month.
₹10,000 a month into an equity SIP at 11% from age 25 to 60 ends near ₹4.6 crore. Start at 35 instead and the same SIP ends near ₹1.4 crore. The 25-year-old invested ₹42 lakh of their own money. The 35-year-old invested ₹30 lakh. The ten-year head start was worth ₹3.2 crore.
Waiting to invest until you 'have enough'. The variable that matters most is not the rupee amount; it is the number of years. ₹500 a month started today beats ₹5,000 a month started in five years.
A 60-second lesson on this, with a worked drill, lives inside the Finlo app. Free, forever, on the basics.