Hackers are children at heart. They can't forget the beauty of playing with things, the joy of creation, of making their ideas real. They are mappers (in the sense from The Programmer's Stone), they hate conformism and rules, and exhibit highly logical thinking. Many like science, and admire the way great scientists think. (Richard Feynman's memories, "Surely you're joking, Mr. Feynman" is one of my favorite books) They are overly confident in themselves; as Yoda put it, "Try not. Do or do not. There is no try." They learn by doing, and any other way of learning seems artificial. You don't first learn and then apply your knowledge; you learn by sinking yourself in the deep shit and then getting out. Quite often, they are regarded by friends (if they have them...) as either outcasts or geniuses.