There are some people with limited capabilities that can’t figure out simple personal finance.
Yet, they are experts on every subject ever conceived.
Lots of experts here too. Just look at a sampling of our cardboard slinging ranks, we have preload "day trading" millionaires, economic theorists, Wall Street wannabes, vaccine virologist's, marxist pontificators, beer aficionados, hub attorneys, gourmet critics, sports betting gurus, substance abuse counselors, off hour-mechanical engineers, marital shamans, footwearology advisors, etc.