Compound interest gets taught in like middle school. The same time we get taught percents and stuff. That said "compound interest" is and any sort of interest

Compound interest gets taught in like middle school. The same time we get taught percents and stuff. That said "compound interest" is and any sort of interest is kind of futile if, like a credit card, the principle is constantly changing, it's also a bit hard to scare people into frugality by telling them if they put these steaks on credit they'll have to pay $12 dollars more later. The numbers don't get scary until well into "they already knew they shouldn't do it" territory.