When Should We Start Learning How to Be Agile?

Why wouldn't we want to teach agility along with reading, writing, and arithmetic?

I was recently reading the book by the Indian philosopher Jiddu Krishnamurti On Education, which talks about the need for schools to educate "integrated" beings, to make them conscious and reflective rather than "dumbing them down" with knowledge not to be discussed.

Which then got me thinking about the subject of agility: Why aren't we teaching agility in grade school? Indeed, my research on the Net in terms of agility learning initiatives at school did not yield much at all.