In the story of the Buddha's Enlightenment, the Buddha had spent many years following ascetic practices in his search for the truth. Close to death as a result of these hardships, he realised that this was not the way, and after eating a meal decided to sit in meditation as he had done naturally as a child. As he sat in meditation, many thoughts, feelings and memories arose which could have distracted him from his purpose, but the Buddha continued to sit. As the morning star arose he gained a deep insight into the nature of existence.
This insight is central to the teaching and practice of Buddhism, and we traditionally celebrate the Festival of the Buddha's Enlightenment at the beginning of December each year.