In I Am Malala, what is the prologue about?

In the Prologue to I Am Malala, Malala Yousafzai tells us about that fateful day when she was almost murdered. The day had started out like any other; Malala and her classmates were on the bus, heading off to school like millions of other children the world over. Normally, Malala would walk the short distance to school, but, as her father's an outspoken critic of the Taliban terrorist organization, her mother thinks that the bus is safer for her.
Unfortunately, this turns out not to be the case. As the bus approaches the school, it's suddenly stopped by an armed member of the Taliban. He boards the bus and asks which girl is Malala. No one answers, but as Malala is the only girl not wearing a burka, the terrorist quickly discovers her identity and promptly shoots her three times.