There are many, many posts and blogs and articles and sentiments about the art and act of gratitude. It is widely understood that gratitude is the act of being grateful for "something." I have seen people use it to express being grateful for "Pokemon Stops" and butter pecan flavored ice cream, just to name a few of the odder ones.
But spiritually, gratitude is about having a grateful heart in all circumstances. It is about being grateful for the little things, yes, but also about seeing the worth in who we are. Seeing how the abundance of what we have been given is the opportunity to compassionate and merciful to others. It is about how we love one another with an open heart.
"Grateful is the heart,
That sees the worth of others,
And gives of oneself."