Self Fulfilling Prophecies?

So I want to write a long, boring, pity post for myself right now, and I am trying to resist that urge.  I do not want to treat this blog like a fucking live journal.  I just have a better understanding of my feelings when I write them down.  I also don't start crying like a baby when I write my feelings out, whereas if I said them out loud I would be a blubbering fool.

I guess we all have to be a little self indulgent at times, right?

So what is the deal with self fulfilling prophecies?  

"The self-fulfilling prophecy is, in the beginning, a false definition of the situation evoking a new behaviour which makes the original false conception come 'true'. This specious validity of the self-fulfilling prophecy perpetuates a reign of error. For the prophet will cite the actual course of events as proof that he was right from the very beginning."

Now how does one stop this from happening?  I mean you can trick yourself into thinking something, but deep down you always know what you really feel, even if you can't say it out loud.  Do my unconscious actions affect how others perceive me and therefore condition them to fulfill my prophecy as well?