How to unlearn pessimism

For adults, one of the most important lessons to learn in life is the necessity of unlearning. We all think that we know certain things to be true beyond doubt, but these things often turn out to be false and, until we unlearn them, they get in the way of new understanding. Among the scientific certainties I have had to unlearn: that upbringing strongly shapes your personality; that nurture is the opposite of nature; that dietary fat causes obesity more than dietary carbohydrate; that carbon dioxide has been the main driver of climate change in the past. I came across a rather good word for this kind of unlearning—"disenthrall"—in Mark Stevenson's book "An Optimist's Tour of the Future," published just this week. Mr. Stevenson borrows it from Abraham Lincoln, whose 1862 message to Congress speaks of disenthralling ourselves of "the dogmas of the quiet past" in order to "think anew." The Rational Optimist