Understand How Compound Interest Actually Works in Your Favour

Most people understand compound interest in theory and fail to take it seriously in practice because the numbers over a lifetime are genuinely hard to believe until shown. The ten-year starting age gap between two otherwise identical savers produces a result that is consistently surprising. This shows the maths, explains why it matters, and names the one common decision that quietly dismantles the effect.

Explain compound interest to me as though I have never properly understood it, including why it is significantly more powerful than most people realise when given time. Use a concrete example with real numbers at two different starting points: someone who starts investing at 22 versus someone who starts at 32, both investing the same monthly amount until 65. Show the actual gap. Then explain the one decision that most undermines the compound effect and that people make without realising the long-term cost.