Thanks for the Memory

Slate magazine recently published a couple of stories about the arrival of new memory drugs and memory enhancement techniques.  These will be godsends for an aging populace suffering from mild cognitive impairment.

What is probably more interesting is why we remember what we do.  Certainly we remember what interests us (and excites us, motivates us, drives us, etc), and we forget what doesn't.

The amygdala (in the center of the brain) helps to process and categorize our experiences.  Is the structure of the amygdala different among the population, leading boys to be more interested in trains and girls more interested in dolls?  Is it responsible for causing some to be interested in seeking power, whereas others are only interested in seeking approval?