That's why I keep telling people about Scott Sumner, market monetarism, and NGDP level determinism - it might not let you beat the stock market indices, but you can end up with some really bizarre expectations if you don't know about the best modern concept of "tight money" and "loose money". E.g. all the people who were worried about hyperinflation when the Fed lowered interest rates to 0.25 and started printing huge amounts of money, while the market monetarists were saying "You're still going to get sub-trend inflation, our indicators say there isn't enough money being printed."

Beating the market is hard. Not being stupid with respect to the market is doable.