It snowed a couple of days ago, and i rushed out of the house before i shoveled the front step. A day later, my footprint is frozen in place.
This trace of yesterday's step is a good description of karma. We are laying down the tracks for our neural networks all the time. Listen to the news, feel afraid or angry, and thereby build the habit of fear or anger. Feel grateful for the blessings of your life today--beautiful snow, for instance. Spend 30 seconds enjoying the snow and begin to build the habit of joy and happiness.
What track, what trace do you want to leave behind for tomorrow? And the day after that? And the year after that?