I've slowly come to realize through personal interactions that a significant portion of the people who complain the loudest about taxes don't really understand

I've slowly come to realize through personal interactions that a significant portion of the people who complain the loudest about taxes don't really understand them. Namely the two topics that came up in this thread. 1. The difference between marginal tax rate and effective tax rate. 2. The key motivating reason for a progressive tax policy vs. a flat tax.