Glass half full or half empty?

My glass is usually half full.  I have a very hard time being around people who are not optimistic.  I am not sure this is a learned trait or one you are born with but I have always been this way, so despite bad things that have happened, I have a good outlook on most things.
I am finding that the pessimist is almost always negative.  You can talk about just about anything and that person will find the negative in it.  Pessimists tend to think everyone is out to get them, they are rarely grateful and they have a hard time letting go of the past.  I am also finding they can support their negativity with facts.  This type of person is difficult to boost and takes so much energy from others around them that the glass that was half full now becomes a glass that needs to be filled with alcohol!
Just think about how nice it would be to be surrounded by people who overcome the bad or negative things going on by being proactive, positive and uplifting! I recognize the world is not a perfect place, that there are horrible things that happen and life isn't all love, peace and happiness.  But, in all that, in each day, there must be a way to find some good.
There is an Indian proverb that a grandfather was teaching his grandson about life and how life is like a terrible fight between two wolves.  One wolf is evil and full of hate, envy, sorrow, regret, lies, superiority, ego, etc.  and the other wolf is good and shows love, goodness, peace, hope, kindness, and truth.  The two wolves are fiercely battling each other all the time and the grandfather says these same things are inside each of us.  The grandson thought about it for a moment and asked his grandfather-- which wolf wins?  And the grandfather answers... the one you feed.