Importance of Gratitude

In Jesuit spirituality, the examination of conscience popularized by St. Ignatius of Loyola, is made up of  five steps. The first step is to reflect upon things you are grateful for and give thanks for them.
(My summer reading group just finished reading Fr. James Martin's excellent book, "Jesus-A Pilgrimage" and in that book Fr. James lists the five steps.)

Also....
"A grateful mind is a great mind that eventually attracts to it great things."
Plato

And....
"If the only prayer you ever said in your life was thank you, that would suffice."
Meister Eckhart, Christian mystic