The world has seen Malala Yousafzai grow up.
At age 11, she went from an average Pakistani child living under Taliban rule to an outspoken advocate for girls' education. By 15, she'd faced an assassination attempt that she was lucky to survive. And by 17, she'd become the youngest person to win a Nobel Peace Prize.
Today, Yousafzai turns 21. She's spending the day in Brazil, doing what she's done on past birthdays: speaking with girls who aren't able to go to school.
"Every year on my birthday I...