Forecasting markets-perspective

Whenever I see a fit personality, I conclude that person should be exercising well. In the same manner if I see a person doing exercise and his schedule then I should be able to tell how fit and unfit his body turns out to be. This needs keen observation and sense of understanding of exercise and human body. Also how these relations existed historically.
How this relates to economy and trading. To undertake trading as a serious business it needs understanding of how various movements can happen. What scenarios can prevail? Strong economies are symbols for stronger factors leading to growth. So what factors contribute towards growth can be inferred by looking at economic indicators. If that is the case then why we make so many poor judgments with regards to understanding economy. Markets (people) are collectively blind and individually wise. They swing from one side to other when cool breeze pass by them. In other words as Benjamin Graham said in the short term markets are like voting machine, but over the long term they are weighing machine.
When looking at individual economic indicators we can tell what is happening in that sector. But we fail to predict what will happen to economy as a whole. Economic indicators are a snapshot of the economy at a particular point of time. Extrapolating the economic potential from scattered economic indicators with some empirical reasoning might be akin to predicting stock markets with number of sun spots. No doubt, economic indicators play a role in measuring the economy. There is one aspect which we might be missing. People adjust their activities according to market environment. A classic example is cut back (adjusting) in personal consumption with a gloomy outlook of economy. Sophisticated predicting models may be adaptive and also they can factor most of the changes and kinks in economic growth but they cannot assimilate the human nature. Human nature can be detected by human alone. There are plenty of human actions that can be automated but to predict a human you need a human. Similarly to predict markets you need humans. Therefore trading remained as a human activity since the dawn of civilization. To predict the markets we need, flair to understand and relate the past. A good understanding of economic indicators and their functional relations to traded instruments. On top of this it requires a human touch of understanding human behavior. By blending all these insights properly we can come up with a good forecast. So for instance to predict gold prices, we need to understand the nature of this commodity, its historical performance under various environments (inflation-deflation). From here we need to understand forces that will drive the price of gold. Towards the end market madness need to be included to come up with a genuine forecast.
This tells me clearly to trade an instrument, I need to know its past, present and market madness.