Why do we think we're better prepared for job interviews than we are? Why does no one act on climate change? Why do we over think when something bad happens to us? Renowned psychologist Professor Woo-kyoung Ahn devised a course at Yale called 'Thinking' to help students examine the biases that cause people so many problems in their daily lives. It quickly became one of the university's most popular courses. Now, for the first time, she presents key insights from her years of teaching and research. It's well known that our minds are tripped up by error, cognitive bias and prejudice. But knowing that isn't enough: the thinking problems still exist. In this clear guide, Professor Woo-kyoung Ahn gives clear and practical steps to actually change our thinking. The natural follow-up to Daniel Kahneman's Thinking, Fast and Slow, Thinking 101 shows how we can improve not just our own daily lives through better awareness of our biases, but the lives of everyone around us. It is required reading for everyone who wants to think - and live - better.