When I Was 17, My Father Was So Stupid, I Didn't Want To Be Seen With Him In Public. When I Was 24, I Was Amazed At How Much The Old Man Had Learned In Just 7 Years.
When you know both yourself as well as your competition, you are never in danger. To know yourself and not others, gives you half a chance of winning. Knowing neither yourself or your competition puts you in a position to lose.