from chapter 4, "A Magic Kingdom," in Naturalist by Edwin O. Wilson.
Consider how long-term memory works. With each changing movement, the mind scans a vast landscape of jumbled schemata, searching for the one or two details upon which the decisive reaction will be based. The mind with a search image is like a barracuda. The large predatory fish pays scant attention to the rocks, pilings, and vast array of organisms living among them. It waits instead for a glint of silver that betrays the twisting body of a smaller fish. It locks on this signal, ruches forward, and seizes the prey in its powerful jaws. Its singlemindedness is why swimmers are advised not to wear shiny bracelets or wristwatches in barracuda waters.
The human mind moving in a sea of detail is compelled like a questing animal to orient by a relatively few decisive configurations. There is an optimum number of such signals. Too few, and the person becomes obsessive-compulsive; too many, and he turns schizophrenic. Configurations with the greatest emotional impact are stored first and persist longer. Those that give the greatest pleasure are sought on later occasions. The process is strongest in children, and to some extent it programs the trajectory of their lives. Eventually they will weave the decisive images into a narrative by which they explain to themselves and others the meaning of what has happened to them. As the Talmud says, we see things not as they are, but as we are.