Toxic is produced when we are sad, stressed and negative. Unlike animals, all of us cry for several years during our childhood days. We are stressed while going to school, especially during examinations. Parents, teachers, fellow students and our inability to cope with so many challenges creates stress that is very harmful for the brain. All of us face negative emotion such as fear, anger, and anxiety and so on. Apart from these, our food, pollution and lifestyle often cause damages to our brain. The Glial cells which are supposed to protect the neurons will clean up the toxic while we are sleeping. Like a vacuum cleaner, the glial cells wipe out some of our memories while taking away the toxic produced during the day time.