What I mean is that often people think they have a formula that works, because it appears to pass all tests including back testing. But what I've gleaned generally happens, is that in due course of time ,is that the formula stops working. So it's only in hindsight that they realize that they were not correct.
On to your point - yes of course people will (and should) attempt things that they believe might work. There is no way to have a crystal ball. All I'm trying to say that consistent success appears very rare when it come to the stock market from what I've heard. The only consistent success in the stock market that I'm aware of, when it come to ordinary mortals is through insider trading etc. which is not an option for most of us.
On to your point - yes of course people will (and should) attempt things that they believe might work. There is no way to have a crystal ball. All I'm trying to say that consistent success appears very rare when it come to the stock market from what I've heard. The only consistent success in the stock market that I'm aware of, when it come to ordinary mortals is through insider trading etc. which is not an option for most of us.