It seems like a simple goal: All kids should go to primary school.
People began talking about it in the 1960s. And they kept talking about it. "Everyone thought it was pretty doable; it wasn't too big of a deal," recalls Aaron Benavot, director of UNESCO's Education for All Global Monitoring Report.
But for lots of reasons — cutbacks on government spending, no schoolhouse within an easy commute — it just wasn't happening. So in 2000, 164 nations got together and pledged "Education For All" by 2015.