The best investors in the world have more of an edge in psychology than in finance.—-Morgan Housel, Motley Fool
This is so true! Most investing problems are behavioral, so having an edge in psychology is very meaningful. You will tend to do well if you are more disciplined (less panicky) and more patient than your competition. This quote is from a longer article that I saw featured on Business Insider. You can read the whole list here.