In our last +1, we talked about the research on the fact that The Pen Is Mightier Than the Keyboard: Advantages of Longhand Over Laptop Note Taking. Today I want to talk about another way to make what we're learning stick. We're going to consult with Barbara Oakley on this one. Barbara taught one of the most popular classes in history. Nearly 2 million people from 200 countries have taken her Coursera class called Learning How to Learn. She also wrote a book on how to learn called A Mind for Numbers where she tells us: "The legendary Charles Darwin would do much the same thing. When trying to explain a concept, he imagined someone had just walked into his study. He would put his pen down and try to explain the idea in the simplest terms. That helped him figure out how he would describe the concept in print. Along those lines, the website Reddit.com has a section called 'Explain like I'm 5' where anyone can make a post asking for a simple explanation of a complex topic. You may think you really have to understand something in order to explain it. But observe what happens when you are talking to other people about what you are studying. You'll be surprised to see how often understanding arises as a consequence of attempts to explain to others and yourself, rather than the explanation arising out of your previous understanding. This is why teachers often say that the first time they ever really understood the material was when they had to teach it." That's Today's +1. Want to master something? Explain it to someone. Like they're 5. TODAY.