Up until a few hundred years ago, childhood only lasted about 11 or 12 years. Even with year-round schooling, children are getting way more of a childhood than they ever used to in the history of our race. Especially these days, kids have more distractions than ever before.
The sad thing is that schools in the US are actually shortening the school year as a way to deal with budget cuts. I honestly wish that Obama had focused on education reform before trying to tackle health reform.