If there is one thing that makes you different from other animals, it is your ability to think. Humans don’t just react to the world as it is: We reflect on the past, imagine what could be, and then plan ways to make our thoughts become reality. Our brain’s advanced outer layer, or cortex, enables us to remember past events and predict the future consequences of our actions before we make decisions. We can think about thinking, and use language to exchange these thoughts with others. American Museum of Natural History