591. We scream out when we are really happy, and our hypothalamus in our brain can't distinguish the difference between good happiness and sorrow.

592. Babies start to process language just like grownups after a couple of days of being born.

593. The 'self-image' is the key to human personality and human behavior. Change the self image and you change the personality and the behavior.

-Maxwell Maltz

594. There's only one requirement of any of us, and that is to be courageous. Because courage, as you might know, defines all other human behavior. And, I believe - because I've done a little of this myself - pretending to be courageous is just as good as the real thing.

-David Letterman

595.!We have compiled a list of these most interesting psychology facts that may help you understand yourself and others better.

596. Some of us are actually afraid of being too happy because of the fear that something tragic might happen next.

597. People who spend more time in the sun are likely to be happier.

598. We are not human beings having a spiritual experience. We are spiritual beings having a human experience.

-Pierre Teilhard de Chardin

599. The most powerful weapon on earth is the human soul on fire.

-Ferdinand Foch

600. It is an ironic habit of human beings to run faster when we have lost our way.

-Rollo May