Thinking is one of the most fundamental abilities that sets humans apart from other living beings. But have you ever paused to wonder—why do we even think? At first glance, it may seem obvious: we think to solve problems, make decisions, and understand the world around us. But thinking goes much deeper than just daily choices. It helps us plan for the future, reflect on the past, imagine things that don’t yet exist, and explore the meaning of life itself. Our thoughts shape our identity, guide our emotions, and influence our actions. From basic survival to complex creativity, thinking is the invisible engine that drives everything we do. In this introduction, we begin to explore not just how we think, but why—uncovering the reasons behind the most powerful tool of the human mind.