Behavioral economics integrates insights from psychology into economics. Going beyond the bounds of rationality and self-interest of economic agents, behavioral economics is concerned with the effects of psychological, social, and cognitive factors on the decisions of individuals and groups. In the lectures, we will look at the most important cognitive biases as well as their causes and consequences. The students will learn how people behave under uncertainty, how they make predictions for the future, how they remember and evaluate the past, if they make consistent decisions over time, and what makes them happy. They will also learn how people perceive themselves, why they have self-control problems, when they feel regret, why default rules have a big impact on human behavior, what is perceived as fair, and how the desire for fairness affects behavior. We will look at many examples from different areas of life, such as sports like football, marathon, golf, or baseball, playing Roulette in a casino, job interviews, organ donations, Facebook ads, the real estate market, the prices of taxis, or the ‘Black Lives Matter’ movement. We will watch some videos and see that cognitive biases are often very pronounced in young children, but don't completely disappear in adults. We will also play games in the classroom and compare the results with the results of research studies in psychology and behavioral economics. We will address questions such as: Why do people sign long-term contracts with a gym and then do not go? Is it a good strategy for a football club to fire the coach in case of failure? Does money make us happy? The goal of the course is to provide an overview of the key insights of behavioral economics in an entertaining and hopefully lasting way and to help the students to understand human behavior in its complexity.