I don't have much to say about this subject, except that I don't like it: it slows you down and takes away the control you have over yourself.
But it stays in all of us, like that itch on your back you simply can't get to; but if you don't think about it you'll just end up forgeting all about it.
Knowing what you're dealing with will obviously help you deal with it.
So go to this link and read the whole thing... yes, everything.
http://people.howstuffworks.com/fear.htm/printabl