The main idea of Malala Yousafzai's memoir is the importance of world peace. Other prominent ideas include the importance of gender equality and religious freedom, all causes Malala has courageously championed.
When Malala received the first National Peace Prize from the Pakistani government, her efforts, including having written about life under the Taliban for the BBC and taken the lead role in a documentary about Islamic extremism, brought her to the attention of the Taliban and made her a target. She was shot, and the struggle to survive and recover was immense. Her entire struggle formed part of her quest for world peace.
The main idea of I Am Malala can be summed up in the address Malala made to the United Nations on her sixteenth birthday. In her speech, she made it clear that nothing she had been through would deter her from continuing to work toward and fight for world peace. The fact that the Taliban is still actively targeting children is something that Malala continues to speak out against.
The fact that she was nominated for and won the Nobel Peace Prize tells us that her ideas resonate around the world. Malala has become a symbol of the fight against terrorism and against the Taliban.