Once, on a mindfulness retreat, I remember our instructor asked us to do one of those odd exercises that are a specialty of meditation teachers. He got us to stand in a circle, then he asked us all to take a step forward. After a few seconds of silence he said, “Now try not to have taken that step.” I had never heard—or more importantly experienced—anything that struck me more powerfully with the pointlessness of certain regrets.

Above all, I had never so clearly understood the difference between teaching by speaking and teaching by experience. My surprise and confusion, the hesitation and agitation of my mind and the puzzlement of my body conveyed all there was to know about the impossibility of undoing and the pointlessness of regret.

-Looking at Mindfulness: 25 Ways to Live in the Moment Through Art by Christophe Andre