Even though we as college students are not that old, we sometimes think back on an event in our life and ask, "what was I thinking". If only I knew what I know now. That is what Chapter 10 is basically about, how and why we develop. Both Erickson's Eight Stages of Development and Piaget's Four Stages of Cognitive Development, as seen above, are included in this chapter to help explain how our way of thinking and looking at things evolved. As infants we can only think about what is happening at that given moment. As we age we can start to think into the future, but we may not be able to fully rationalize things. Piaget proved this through his water conservation tasks where he poured one glass of water into a taller glass and asked the child if there was more, less or the same amount of water. Because the water was now in a taller glass, the child thought there was magically more water. Then, as we continue to grow older our perspective changes and we begin to reason and think of things hypothetically. By the time we are in Erickson's final stage of "Aging" we look back at our life hoping to see a good person with a satisfaction about what we did with our lives. With any luck, whenever we look back at our "what was I thinking" moments we will laugh at how little we knew then.