Sociologists at one university recently completed a study on regret. In it, they examined whether people felt more regret over what they had done or what they had failed to do. The researchers found that people’s regrets over their actions or inactions were roughly even when asked about the past week. Nearly the same number said, “I wish I hadn’t done that” as those who said “I wish I had done that.” But when asked to consider their life’s largest regrets, the vast majority said they were more troubled about missed opportunities. As John Greenleaf Whittier wrote, “Of all sad words of…