This is one of the most ridiculous posts I've ever read. And that is saying a lot.
Trading is hard, and it isn't right for everyone. However, the fact that we cannot know something completely or perfectly doesn't mean that we can't learn to do it or learn some part of it in which we can be effective. Any complex art, science or similar human endeavor is going to be larger than the capacity of any one person to know it all. That does not mean that a person, through diligent application of effort and maybe some natural skill, cannot become a master at it, even though it might take years or a lifetime.
I believe that, if someone wants to learn to trade, he needs to get to know himself -- his skills, available time, strengths and weaknesses -- the market he wishes to trade, the broker he is using, the software he is using, and then practice one or two basic setups hundreds of times, until he can execute them perfectly each time and can show a consistent positive expectancy. He doesn't have to know every indicator, every market, every theory and nuance; to claim that he "can't learn" something simply because it is complex or changing is complete nonsense.
Consider jiujitsu. There are thousands of techniques, and it is constantly evolving. The best players, though, aren't necessarily those who know thousands of moves, but who have mastered the basic principles and can execute a few effective moves with proper timing, confidence and efficiency. Getting there takes years of practice, hundreds or thousands of repetitions, and a lot of mistakes were made along the way. It isn't easy, and only one in a thousand can do it.