Sometimes facts are so strong which can be easily seen in future. I agree with mental part and I would say it's more common sense . Some say intuition. Regarding investment I only would add that my $100k portfolio had a return% of 24 since May 1st. It sounds too good to be true but impossible is not exist in my book! I know my industry and I would add being passionate about industry or areas you are investing goes a long way! It works for me at least. :-)