Cognitive Skills You Need for the 21st Century begins with the Future of Jobs Report 2018 of the World Economic Forum that describes trending skills through the year 2022. To assist with the development of these skills, the book describes techniques that should benefit everyone. The 20 chapters occupy 6 sections on acquiring knowledge (comprehension, action, categorization, abstraction), organizing knowledge (matrices, networks, hierarchies), reasoning (visuospatial reasoning, imperfect knowledge, strategies), problem-solving (problems, design, dynamics), artificial intelligence (data sciences, explainable AI, information sciences, general AI), and education (complex systems, computational thinking, continuing education). Classical research, recent research, personal anecdotes, and a few exercises provide a broad introduction to this critical topic.