Learning Lessons in Stock Market Can Be Dangerous.

Learning lessons in the Stock Market can be surprisingly dangerous. Although, some lessons can be learned but it is not universally true that learning a lesson can be useful.
The trap that when you think you have learned a lesson and you want to apply it next time it may not work! In addition it may lead to a disaster.
The reason when you drew conclusion from the first lesson you discover that when you want to apply it you realize that new parameters that may not have appeared at the first lesson is coming back to bite.