My daughter has 8.5 years of college and a great memory, but many years ago when she was in high school she asked me how compounded interest worked. I was floored. I opened up an account for her and put 10 thousand dollars in it and told her to watch. She wouldn't forget now, that was almost 20 years ago. By the time she's my age the answer to how it works will be even more obvious, it already is.