Who doesn’t have second thoughts? What-ifs? If-onlys? Why-did-I’s? and Why-didn’t-I’s? We all look back on our lives and wonder what might have been. And we should, says author Ralph Keyes. In Second The Power of Positive Regret, Keyes argues that regrets are a marker of full lives. “Anyone without regrets has lived a meager life indeed,” he writes. “Regrets are evidence that we’ve lived an active life, taken chances, made decisions, and wished we had made some differently.”With compelling illustrations from the many interviews he’s conducted, as well as research done on this subject, Keyes has developed a uniquely affirming attitude toward regret. Since it suggests that we are taking responsibility for our decisions, he writes, having regrets is far better than making excuses or blaming others for aspects of our lives we wish had gone better. Keyes goes further, suggesting ways in which second thoughts can enrich our lives. Musing about roads not taken provides an opportunity for thoughtful reflection, he says, a source of self-awareness, and a tool for growth. Looking back on decisions we regret can suggest ways to make better choices in the future. This is why, Keyes concludes in his thoughtful, reassuring book, “second thoughts are not only an inevitable but an invaluable part of a life fully lived.”