2. The ability to realize there is no such thing as true knowledge, for in the eyes of another man, what you know, could very easily be wrong to that person
By placing the opinions of every person in the world together, you will find that there are very few "Facts" that are not seen as incorrect by at least one person
one can only express what he/she "knows"
we're getting into quantam physics here, the brain percieves only what it wants to