Mentally subtract positive events. To take the hurt out of a regret, try a mental trick made famous in the 1946 movie Its a Wonderful Life. On Christmas Eve, George Bailey stands on the brink of suicide when hes visited by Clarence, an angel who shows George what life in Bedford Falls would be like had he never been born. Clarences technique is called mentally subtracting positive events.

The Power of Regret by Daniel H. Pink