Have you ever met individuals with insane and brilliant ideas that got you wondering, how come he knows all this and it's not even reflected in his life? Some could give you real business ideas that could change a whole generation but that's all they can do, they can't bring it to reality and all their ideas only end on the discussion ground and never come to life.
Some of this people you explained here are not insane but people see them as insane because of there insane explanation or discovery. You know that when someone is doing exceptional thing which others can not do it becomes insane. Some people are good teachers but are not good in doing what they teach, why some can't teach but depend on what the preacher preaches for them to tap from the knowledge. Life is a mistry which you can not explain everything. Some things are really unexplainable about life. That's why people are not perfect. Everything can not complete in one person. Some people's grace is only to educate others to learn and becomes better person in the future, expecially the teachers. Some people who can do what they teach them might be rich in the nearest future, after person he might have help will have becomes rich, will come back for payback of what he has impacted in his life.
It is a valid point that people may perceive exceptional abilities or ideas as "insane" simply because normally they don't understand them or haven't seen them before. Its true that not everyone has the same strengths or weaknesses and some people are naturally better at teaching or learning than others. Also I think it's important to recognize that everyone has unique talents and abilities, and that success often comes from building on one's strengths rather than trying to be well-rounded. Those who excel in a particular area may be able to leverage their skills to achieve great things, while those who are less skilled in certain areas can still make valuable contributions by learning from others and applying that knowledge in meaningful ways.