why so angry

Why is it that people get so angry over things they can't control? Been there done that, trying oh so hard to stop. I know a person that goes off the deep end in regard to politics. The evil rich right, does everything wrong, lies, can't be trusted and will crush anyone who disagrees. And everyone on the left is out to save the world, but can't because  Such hate and anger come through in status updates. Deep down a decent person, but I think so full of jealousy and envy that all that is buried. Why is it someone with  a lack of motivation feels entitled to be given assets from a person that has worked hard?
We don't have much, really not much at all, but I am pretty content, do I wish we had more, who doesn't, but don't wish it to come FROM anyone else. Maybe that is the key, being content where we are, do what we can, be happy with what we have.
I have always taught my kids that they can be anything that they want to be, don't pick a career based on potential income, but because it is your passion. If you do what you love, you will never work a day in your life. BUT, if you choose a $40k career, be prepared for a $35k lifestyle. Live within your means, work for what you need, don't expect a hand out, and help others along your way.
Life's too short to get so angry over something that we have so very little control over, and I m going to work hard at no going there anymore...