Left in the Dark?

If you find that you are often 'the last to know' the reason may be your way of receiving information.  
Some people, if they have found, with experience, that a particular person in their life, is rather reactive, will simply not tell that person things.
If you tend to be instantly expressive, it can be delightful when  it's  positive, happy news;  others will truly enjoy imparting good news to you.  They may look forward to your childlike enthusiasm and  they will enjoy your reaction.  On the other hand, if you are easily excited, quick to anger, abrupt, impulsive, many people will choose not to deal with that.
It seems unfair and, yet, I've heard this so often in my office:  "I didn't tell her because I didn't want to hear it." or, "I was afraid of what he'd do if I told him.", or "I knew what she'd say and I just didn't want to go there with her", etc.
A simple lesson:  If you are the expressive, excitable  type, try to learn to choose when and in what circumstances you share your reactions.
Think for just a few seconds before you speak---give yourself a chance to make a choice.
Respond rather than react.