“A number of years ago, I stayed for about a week in a farmers house in Connemarra on the west coast of Ireland. He seemed to be always singing and whistling and was full of humor.  I asked him the secret of his happiness, and his reply was:
“It is a habit of mine to be happy.  Every morning when I awaken and every night before I go to sleep, I bless my family, the crops, the cattle and I thank God for the wonderful harvest.”

This farmer had made a practice of this for over forty years.  As you know, thoughts repeated regularly AND systematically sink into the subconscious mind and become habitual. 

He discovered that happiness is a habit.”

~The Power Of Your Subconscious Mind
Dr. Joseph Murphy