As I said in another comment, I believe we are generally very poor at telling how we rate on any given scale, unless we have something very tangible - an object

As I said in another comment, I believe we are generally very poor at telling how we rate on any given scale, unless we have something very tangible - an objective score (like in a game), lots of outside confirmation, etc. Most of us think we are better drivers than we are. When you do not have as much outside feedback, it's easier to talk yourself into believing anything. One of the best applications of this is to be more positive and happier.