Explain how the principle of compound interest significantly amplifies the impact of micro-investments over an extended period, using a hypothetical scenario.

Compound interest is the cornerstone of long-term wealth building, and its effect on micro-investments is particularly profound, albeit often underestimated. It's the process where the interest earned on an initial investment also starts earning interest, creating a snowball effect. This amplification is not linear; it accelerates over time, transforming even the smallest contributions into substantial sums. Let's illustrate this with a hypothetical scenario: Imagine two individuals, Sarah and David, both starting at age 25. Sarah decides to invest $10 per week, consistently, into a diverse micro-investment portfolio averaging a 7% annual return. David, initially skeptical about the impact of such small amounts, does not invest but decides to do so later. Over the first five years, Sarah invests $2,600 in total ($10/week 52 weeks/year 5 years). At the end of this period, due to compound interest, her investment has grown to approximately $2,986. This might not seem like much compared to the initial contribution, but this is merely the beginning. Now, fast forward another 10 years. Sarah is now 40 and, continuing her $10 weekly investment, her total contributions are $7,800. However, her portfolio is now worth approximately $13,585,....