The most basic of all The Laws of Magic is the Law of Knowledge because with understanding comes control and power. The more the person or magician knows about a person or phenomena the more control he has over it. This is an absolute rule which applies to the human organism as well as modern technology.
By knowing a person’s daily routine, if one desires to alter that person’s behavior, all one has to do is change a factor or two and the person’s behavior will probably change. A native may walk a certain path daily, but once he keeps seeing little manikins resembling himself which he believes are signs of danger in the path he will choose another path.
A person with computer knowledge is able to control the computer; whereas, a person without such knowledge cannot operate a computer. A.G.H.
Source: 44.