It's so easy to take an education for granted. An education isn't just about learning to read and write - an education opens an entire world of possibilities. It opens up your mind, it unlocks your imagination and it empowers you to make choices that determine your own path in life.
I was a truly horrible teenager. I lied, cheated, stole, did lots of things that I really wasn't supposed to do... I was utterly poisonous. Now that I'm having my own children, my mother rubs her hands in glee at the thought of mine putting me through what I put her through.
But at the same time as being a self-entitled and over-privileged brat, I was acutely aware of the importance of my education. I always worked hard and did well at school. I knew perfectly well that if I wanted choices in my life; if I wanted independence, security and to have a good time, I needed a good education. I was lucky - it was handed to me on a plate. But I took it, with a less than a modicum of gratitude, and I lapped it up.
Across the world today, 63 million girls are out of school. These girls are unable to make choices over their own future, simply because they don't have access to an education. Even girls who are in school are one and a half times less likely to complete secondary school than boys. There are half a billion women who can't read.
Girls who are not educated are more likely to live in extreme poverty and to lead less healthy and productive lives. However, if a girl completes both primary and secondary school #SheWill marry later, have children later, raise healthier children, and earn more as an adult.
With the establishment of the Global Goals last September, for the first time in history, we have the opportunity to ensure that all girls have access to a quality education. The ambition has been set, now is the time for action.
That's why this week, we launched the #SheWill campaign. In partnership with the UK Government, Global Citizen + CHIME FOR CHANGE are bringing decision makers and leaders together to launch a global action plan that will ensure that no girl is left behind, and that girls don't just go to school - they stay in school and get a quality education.
We need the voices of global citizens to join in, speak out and take action so that we can drive concrete action from global leaders, and hold them to account.
And by taking part, global citizens can win tickets to Global Citizen + CHIME FOR CHANGE Live at the View from the Shard - a night of inspiring speakers and intimate music - headlined by Tom Odell - from the rooftop of one of London's most iconic buildings.
I'm not sure that my own over-privileged children won't be as unpleasant as I was when they are teenagers. But I am sure that in 2030, when they are safely cocooned in secondary school, global citizens will have wholly rejected the current status quo and millions of girls being out of school will be a thing of the past.
But we have some work to do before then.