I have to confess, I don't really like the word "mindfulness." I think it's misleading, and often misused. I believe it's a word that got lost in translation from East to West. The original intention of the word, if you read from some of the buddhist teachers like Tich Nhat Hanh, was to capture a state of being that is fully present and awake, relaxed and alert. The word Mind in eastern teachings most often refers to a place of inner being, inner knowing.
"To identify oneself with the body (ego) and yet to seek happiness is like attempting to cross a river on the back of an alligator."