Weeeelll ... yes you are right. But, human psychology is not infinitely complex. Just like you can train a horse, a dog or a cat to do tricks by adjusting to the psychological nature of each of the species, you can also teach humans new skills. The human mind is good a processing lower level signals extremely well: visual, auditory, hunger, pain, love, desire, fear, danger, all of those things. The human mind is terrible at processing higher order singalling: anything that deals with logic and is handled by the outer gray area of our brain. For any information that is in this category, you need to underestand the ecosystem of control mechanisms involved and target appropriately. You are right, but we do know how this works.