Suppose I were to describe a person to you that you have never met. I could tell you everything that I know about that person right down to the smallest detail. I could impart to you every thought and even every emotion that I associate with this person. I could so thoroughly describe this person to you that it would be “as if” you knew this person too but in reality, you would only have “head knowledge” of this person.
Now let’s suppose that a friend of mine described this same person to you in as great a detail as I have. Would my friend have imparted the exact same “head knowledge” to you that I have? Or, would our descriptions reflect our own bias of that person based on our individual experiences with that person?
Since it is quite unlikely that either of us knew exactly everything that the person was going through or experiencing, or the choices that had to be made depending on varying factors, it is quite unlikely that both of us will draw identical conclusions of the person. It is therefore, reasonable to assume that the head knowledge that I have imparted to you may contain a certain amount of bias that may misconstrue the truth to some degree or another.