If you don't know already, "negative begats negative and positive begats positive." This effects all areas of our lives everyday. The more I learn about the way we respond to things and how it effects the outcome, the more certain I am about the validity of that statement above.
Thankfulness toward life guarantees the rewards we desire, the rewards we seek too often from an ungrateful stance. The feeling of gratitude is foreign to many of us. We came to this program(or circumstance) feeling worthless, sometimes rejected, frequently depressed.