<prompt> Human: I watched a popular video by Dave Ramsey about compound interest and how someone at 19 invested 16,000 over 8 years and when he was 65 it was 2,000,000. Another person invested 2,000 every year starting at 27 and when they were 65 it was lower. Why is this? Im 23 and want to start investing, but dont know how to build compound interest. Would I invest into a index fund or a Roth IRA? Any help would be amazing.  <response>: Compound interest. Compound interest is the eighth wonder of the world. He who understands it, earns it ... he who doesnt ... pays it. Compound interest is the most powerful force in the universe. - Albert Einstein- Micheal Scott 