To comprehend the world around us, we first have to decipher how our brains work. This book outlines a new approach to knowledge and comprehension based on the elucidation of several basic neuronal mechanisms. It explores the crucial fact that unconscious processes and conscious experiences form a continuum and, importantly, introduces the concept of metarepresentations. This fundamental notion captures the essence of being human, namely, what separates us from our evolutionary predecessors. Important examples of metarepresentations are language, mathematics, technology and the arts. The interdisciplinary, integrative approach of this book demonstrates how different disciplines and notions which appear disconnected are actually closely related. Furthermore, this approach elucidates how we think about topics such as mathematics, physics, painting, music and philosophy. Most significantly, it helps us understand the origin of our thoughts, feelings and actions, bringing deep insight and fulfilment or, more precisely, eudemonia.