What Gives?

I by my very nature like to talk, to share.  I genuinely love to ask people questions to know and try to understand what makes them tick.  On the flip side, I most of the time would like to be an open book.  I would like to people to know what makes me happy or sad or angry.  HOWEVER, I am constantly concerned with "Did I share too much?"  "Will this negatively affect the ones I love?"  "Will someone use this against me?"  So, what's the balance?  I mean, why do I love blogs so much?  Because people are willing to share what is in their world.  I find it fascinating.  So, is it okay for me to share details or should I refrain for the sake of the possible negative consequences?  What gives?  What is the appropriate balance?