From the opening lines of the first chapter of the Dhammapada on Choices:
We are what we think.
All that we are arises with our thoughts.
With our thoughts we make the world.
How many times have I read these lines, contemplated there truth, and worked to transform my thinking? But first I must become aware of my thinking, perhaps even become aware that I am alive. How to train the thinking? How to train awareness? By daily diligent practice aided with the support of a community. Wise instruction from one who has journeyed the path provides direction and then some. Time passes and awareness deepens, and then is lost. The mind is fleeting - attention directed, then distracted; pulled away and then hopefully returned.
I follow my breath, planting seeds with my thinking. Habits transmitted to me and honed finer, begin to loose their edge. Patterns of thinking and acting that I developed as my response to the world are slowly revealed, slowly replaced. But their energy is strong, watered by years and even lifetimes of use. Before I am aware, I am once again locked in habit, without a choice. But then I become aware of my thinking, aware of my actions, maybe even aware of my state. A choice becomes possible. Do I direct my thinking, raising my awareness and tasting freedom? Am I alive? Am I breathing? Am I aware of the energy of life within me and around me?
We begin again constantly - when we are fortunate, when we are devoted to waking up to life. Replacing inherited thoughts, adopted thoughts, and the thinking of others & society to which we are constantly exposed is a brave choice. A necessary choice. We are what we think. I'm not sure I even like the notion as it places the burden of responsibility so squarely on me.

