It always drove me crazy when I heard people say: "lf you are angry or hurt, it is your choice!". No dears. It's not. The choice of feeling or not is not a choice. And saying it is, is a lie. What can be a choice, relies in what you are doing with these feelings.
Down here is an easy way to understand how exactly happiness is a question of perception. And how to work on your brain through meditation. Meditation is not for everybody. By understanding and working on perception, you can change the way you see things. The way life gets to you. So look at this TeD talk, and if meditation is not for you, other solutions do exist to change your perception and grow to happiness
Happiness is all in your mind: Gen Kelsang Nyema at TEDxGreenville 2014