IMO most people in the world don't. Some countries have not so bad economy education at schools but most have very primitive. There is a not bad book for children "A Dog Called Money" but most adults can find out that they didn't know economy even at that children's book level. People usually do simple mistakes when they start investing or trading and basic economy education can solve that problem: some people will lose money anyway as not every investment is prospecting, but we'll have less losses based just on wrong understanding of a basic market features.