Thinking is defined as using thought or rational judgment. The process of using one’s mind to consider or reason about something. Thinking is activity of mind. It is mindful work of your own perception and understanding. The critical thinking process starts out with knowledge. All thinking starts with knowledge, whether a little bit or a good understanding of thinking topic. If you can not comprehend what you are thinking about, you cannot think about it effectively. Most of our thinking’s sensory interactive. Thinking can shape the way we sense. Sending for adults is concurrent with thinking. As we sit in class, drive, cook, or even clean; we are sensing with our eyes, ears, and hands. The two most important senses for thinking are seeing and hearing. Our senses play an important role for our brain. Our senses feed our brain as food. A person’s power to remember things is memory. According to Dictionary.com (2012), “Memory is the mental capacity of faculty of retaining and reviving facts, events, impressions, etc. or of recalling or recognizing previous experiences.“ Hidden within our brain is our memory. There are two type of memory. We have short-term memory which we seem to forget entirely and last only about twenty to thirty seconds without rehearsal. Then, we have long-term memory which are the most important for our thinking and last the longest. Without memory there could be no thinking based upon experience. What we think depends both on our ability to remember and on the content of that remembering. Memory that is poor makes it difficult for us to think positively. To make memory easier to recall, we must back up our memory with hard data and write down events that we know we will be expected to remember later. Some ways to encode information is practice and the use of mnemonics. A drug is any chemical you take that affects the way your body works.